diff --git a/pdf.php b/pdf.php
index 516ecc53a..77db9a929 100644
--- a/pdf.php
+++ b/pdf.php
@@ -500,7 +500,9 @@ public function notice_body_content() {
 		 * @since 6.12
 		 * @deprecated
 		 */
-		public function maybe_display_canonical_plugin_notice() {}
+		public function maybe_display_canonical_plugin_notice() {
+			_deprecated_function( __METHOD__, '6.12' );
+		}
 
 		/**
 		 * Notify administrator they are not using the canonical version of Gravity PDF
@@ -510,7 +512,9 @@ public function maybe_display_canonical_plugin_notice() {}
 		 * @since 6.12
 		 * @deprecated
 		 */
-		public function maybe_display_canonical_plugin_notice_below_plugin( $plugin_file, $plugin_data ) {}
+		public function maybe_display_canonical_plugin_notice_below_plugin( $plugin_file, $plugin_data ) {
+			_deprecated_function( __METHOD__, '6.12' );
+		}
 	}
 }
 
diff --git a/src/Controller/Controller_Actions.php b/src/Controller/Controller_Actions.php
index 08434dc93..c6e5772b9 100644
--- a/src/Controller/Controller_Actions.php
+++ b/src/Controller/Controller_Actions.php
@@ -119,6 +119,7 @@ public function add_actions() {
 	 * condition: The function or method to call to determine if a notice should be displayed (Boolean)
 	 * process: The function to handle a successful action. On success the disable_route() method should be called
 	 * view: The function used to display the notice content
+	 * view_class: Optional classes for the notice box, including a `notice-*` state like `notice-warning`
 	 *
 	 * @return array
 	 *
@@ -158,6 +159,11 @@ public function route_notices() {
 			return null;
 		}
 
+		/* Don't run the route conditions, which query the database, on pages that discard the notice anyway */
+		if ( ! $this->notices->can_display_notice_on_this_page() ) {
+			return null;
+		}
+
 		foreach ( $this->get_routes() as $route ) {
 
 			/* Before displaying check the user has the correct capabilities, the notice isn't already been dismissed and the route condition has been met */
@@ -173,8 +179,10 @@ public function route_notices() {
 					]
 				);
 
-				$class = ( isset( $route['view_class'] ) ) ? $route['view_class'] : '';
-				$this->notices->add_notice( call_user_func( $route['view'], $route['action'], $route['action_text'] ), $class );
+				$this->notices->add_notice(
+					call_user_func( $route['view'], $route['action'], $route['action_text'] ),
+					$route['view_class'] ?? ''
+				);
 			}
 		}
 	}
diff --git a/src/Controller/Controller_Install.php b/src/Controller/Controller_Install.php
index 66fc0b99a..3c488a839 100644
--- a/src/Controller/Controller_Install.php
+++ b/src/Controller/Controller_Install.php
@@ -206,6 +206,6 @@ public function check_install_status() {
 	 * @deprecated 6.0
 	 */
 	public function maybe_uninstall() {
-		_doing_it_wrong( __METHOD__, 'This method has been moved to Controller_Uninstall::uninstall_addon()', '6.0' );
+		_deprecated_function( __METHOD__, '6.0', 'Controller_Uninstall::uninstall_addon()' );
 	}
 }
diff --git a/src/Controller/Controller_PDF.php b/src/Controller/Controller_PDF.php
index 2febd1fcc..22311635b 100644
--- a/src/Controller/Controller_PDF.php
+++ b/src/Controller/Controller_PDF.php
@@ -11,6 +11,7 @@
 use GFPDF\Helper\Helper_PDF;
 use GFPDF\Model\Model_PDF;
 use GFPDF\Statics\Debug;
+use GFPDF\Statics\Deprecation;
 use GFPDF\View\View_PDF;
 use GFPDF_Vendor\Psr\Log\LoggerInterface;
 
@@ -204,7 +205,7 @@ public function add_filters() {
 		add_filter( 'gfpdf_pdf_html_output', $add_view_html_debugger, 9999, 5 );
 
 		/* Backwards compatibility for our Tier 2 plugin */
-		add_filter( 'gfpdfe_pre_load_template', [ 'PDFRender', 'prepare_ids' ], 1, 8 );
+		add_filter( 'gfpdfe_pre_load_template', Deprecation::INTERNAL_FILTER_CALLBACK, 1, 8 );
 
 		/* Pre-process our template arguments and automatically render them in PDF */
 		add_filter( 'gfpdf_template_args', [ $this->model, 'preprocess_template_arguments' ] );
@@ -292,7 +293,7 @@ public function process_legacy_pdf_endpoint() {
 			return null;
 		}
 
-		_doing_it_wrong( __METHOD__, 'Legacy PDF URLs are deprecated. Replace with the [gravitypdf] shortcode or PDF merge tags. See https://docs.gravitypdf.com/v6/users/shortcodes-and-mergetags for usage instructions.', '4.0' );
+		_deprecated_function( __METHOD__, '4.0', 'the [gravitypdf] shortcode or PDF merge tags, https://docs.gravitypdf.com/v6/users/shortcodes-and-mergetags' );
 
 		$config = [
 			'lid'      => (int) explode( ',', $_GET['lid'] )[0],
@@ -310,6 +311,9 @@ public function process_legacy_pdf_endpoint() {
 			$this->pdf_error( $pid );
 		}
 
+		/* Record the hit so it can be surfaced in the System Report ahead of the 7.0 removal */
+		Deprecation::record_legacy_endpoint_usage( $config['fid'] );
+
 		/* Store our ids in the WP query_vars object */
 		$GLOBALS['wp']->query_vars['gpdf'] = 1;
 		$GLOBALS['wp']->query_vars['pid']  = $pid;
@@ -323,7 +327,7 @@ public function process_legacy_pdf_endpoint() {
 			]
 		);
 
-		$this->log->warning( 'Legacy PDF URLs are deprecated. Replace with the [gravitypdf] shortcode or PDF merge tags. See https://docs.gravitypdf.com/v6/users/shortcodes-and-mergetags for usage instructions.' );
+		$this->log->warning( sprintf( 'Legacy PDF URLs are removed in Gravity PDF %s. Replace with the [gravitypdf] shortcode or PDF merge tags. See https://docs.gravitypdf.com/v6/users/shortcodes-and-mergetags for usage instructions.', Deprecation::REMOVED_IN ) );
 
 		/* Send to our model to handle validation / authentication */
 		do_action( 'gfpdf_legacy_pre_view_or_download_pdf', $config['lid'], $pid, $config['action'] );
@@ -399,7 +403,7 @@ protected function add_pre_view_or_download_pdf_hooks( $form, $entry, $settings
 	 * @deprecated 6.12 All buffers are auto-closed before a PDF is sent to the browser
 	 */
 	public function sgoptimizer_html_minification_fix() {
-		_doing_it_wrong( __METHOD__, 'This method has been removed and no alternative is available.', '6.12' );
+		_deprecated_function( __METHOD__, '6.12' );
 	}
 
 	/**
diff --git a/src/Controller/Controller_Pdf_Queue.php b/src/Controller/Controller_Pdf_Queue.php
index f9c5debcb..cf7c4227a 100644
--- a/src/Controller/Controller_Pdf_Queue.php
+++ b/src/Controller/Controller_Pdf_Queue.php
@@ -241,7 +241,7 @@ public function queue_async_form_submission_tasks( $entry, $form ) {
 	 */
 	public function queue_dispatch_resend_notification_tasks( $form = null, $entry = null ) {
 		if ( ! is_null( $entry ) ) {
-			_doing_it_wrong( __METHOD__, '$entry argument ignored and now set in self::should_send_async_notification()', '6.13.5' );
+			_deprecated_argument( __METHOD__, '6.13.5', 'The $entry argument is ignored and now set in self::should_send_async_notification()' );
 		}
 
 		/* loop over all form/entries */
@@ -305,7 +305,7 @@ public function queue_async_tasks( $form, $entry ) {
 	 * @deprecated 6.12.0 Caching layer + auto-purge added
 	 */
 	public function queue_cleanup_task( $form, $entry ) {
-		_doing_it_wrong( __METHOD__, 'This method is deprecated and no alternative is available. The temporary cache is automatically cleaned every hour using the WP Cron.', '6.12' );
+		_deprecated_function( __METHOD__, '6.12' );
 	}
 
 	/**
@@ -516,6 +516,6 @@ public function reset_queue() {
 	 * @deprecated 6.11
 	 */
 	public function queue_async_resend_notification_tasks( $notification, $form, $entry ) {
-		_doing_it_wrong( esc_html( 'queue_async_resend_notification_tasks() was removed in Gravity PDF 6.11' ) );
+		_deprecated_function( __METHOD__, '6.11' );
 	}
 }
diff --git a/src/Controller/Controller_System_Report.php b/src/Controller/Controller_System_Report.php
index 53923cf06..586ac3572 100644
--- a/src/Controller/Controller_System_Report.php
+++ b/src/Controller/Controller_System_Report.php
@@ -3,6 +3,7 @@
 namespace GFPDF\Controller;
 
 use GFPDF\Helper\Helper_Abstract_Controller;
+use GFPDF\Helper\Helper_Abstract_Form;
 use GFPDF\Helper\Helper_Abstract_Model;
 use GFPDF\Helper\Helper_Abstract_View;
 use GFPDF\Model\Model_System_Report;
@@ -38,12 +39,23 @@ class Controller_System_Report extends Helper_Abstract_Controller {
 	 */
 	public $view;
 
-	public function __construct( Helper_Abstract_Model $model, Helper_Abstract_View $view ) {
+	/**
+	 * Holds the abstracted Gravity Forms API specific to Gravity PDF
+	 *
+	 * @var Helper_Abstract_Form
+	 *
+	 * @since 6.17.0
+	 */
+	protected $gform;
+
+	public function __construct( Helper_Abstract_Model $model, Helper_Abstract_View $view, Helper_Abstract_Form $gform ) {
 		$this->model = $model;
 		$this->model->setController( $this );
 
 		$this->view = $view;
 		$this->view->setController( $this );
+
+		$this->gform = $gform;
 	}
 
 	/**
@@ -62,6 +74,63 @@ public function init() {
 	 */
 	public function add_filters() {
 		add_filter( 'gform_system_report', [ $this, 'system_report' ] );
+		add_filter( 'site_status_tests', [ $this, 'site_status_tests' ] );
+		add_filter( 'debug_information', [ $this, 'debug_information' ] );
+	}
+
+	/**
+	 * Register a Site Health test for any deprecated functionality in use on this site
+	 *
+	 * The admin notice can be dismissed for good, and the Gravity Forms system report has to be sought out. This
+	 * puts the same detections where WordPress reports the rest of a site's problems, and keeps them there until
+	 * they're fixed.
+	 *
+	 * @param array $tests
+	 *
+	 * @return array
+	 * @since 6.17.0
+	 */
+	public function site_status_tests( $tests ) {
+		if ( ! is_array( $tests ) || ! $this->gform->has_capability( 'gravityforms_view_settings' ) ) {
+			return $tests;
+		}
+
+		$tests['direct']['gravity_pdf_deprecated_features'] = [
+			'label' => esc_html__( 'Deprecated Gravity PDF functionality', 'gravity-pdf' ),
+			'test'  => [ $this, 'deprecated_features_test' ],
+		];
+
+		return $tests;
+	}
+
+	/**
+	 * Run the deprecated functionality Site Health test
+	 *
+	 * @return array
+	 * @since 6.17.0
+	 */
+	public function deprecated_features_test() {
+		return $this->view->get_deprecated_features_test( $this->model->get_deprecated_signals() );
+	}
+
+	/**
+	 * Add the deprecated functionality to the Site Health Info tab
+	 *
+	 * The Info tab is what users copy into a support ticket, so the detections travel with it.
+	 *
+	 * @param array $info
+	 *
+	 * @return array
+	 * @since 6.17.0
+	 */
+	public function debug_information( $info ) {
+		if ( ! is_array( $info ) || ! $this->gform->has_capability( 'gravityforms_view_settings' ) ) {
+			return $info;
+		}
+
+		$info['gravity-pdf-deprecated'] = $this->view->get_deprecated_debug_information( $this->model->get_deprecated_signals() );
+
+		return $info;
 	}
 
 	/**
diff --git a/src/Helper/Fields/Field_Signature.php b/src/Helper/Fields/Field_Signature.php
index e443aaeb0..0641111b2 100644
--- a/src/Helper/Fields/Field_Signature.php
+++ b/src/Helper/Fields/Field_Signature.php
@@ -4,6 +4,7 @@
 
 use GFFormsModel;
 use GFPDF\Helper\Helper_Abstract_Fields;
+use GFPDF\Statics\Deprecation;
 
 /**
  * @package     Gravity PDF
@@ -132,7 +133,7 @@ public function value() {
 			 * @param integer The original image width
 			 */
 			if ( $signature_details !== false ) {
-				$optimised_width = apply_filters( 'gfpdfe_signature_width', $signature_details[0] / 3, $signature_details[0] ); /* backwards compat */
+				$optimised_width = Deprecation::apply_filters( 'gfpdfe_signature_width', [ $signature_details[0] / 3, $signature_details[0] ] );
 
 				/* See https://docs.gravitypdf.com/developers/filters/gfpdf_signature_width/ for more details about this filter */
 				$optimised_width = apply_filters( 'gfpdf_signature_width', $optimised_width, $signature_details[0] );
diff --git a/src/Helper/Helper_Abstract_View.php b/src/Helper/Helper_Abstract_View.php
index e78fff80c..bac788e4e 100644
--- a/src/Helper/Helper_Abstract_View.php
+++ b/src/Helper/Helper_Abstract_View.php
@@ -108,6 +108,10 @@ final protected function load( $filename, $args = [], $output = true ) {
 
 		$args = array_merge( $this->data_cache, $args );
 
+		if ( isset( $args['content'] ) ) {
+			_deprecated_argument( esc_html( $this->view_type . '/' . $filename . '.php' ), '6.4.0', "Use \$args['callback'] instead" );
+		}
+
 		if ( is_readable( $path ) ) {
 
 			if ( $output ) {
diff --git a/src/Helper/Helper_Misc.php b/src/Helper/Helper_Misc.php
index 7662064b9..3b17db283 100644
--- a/src/Helper/Helper_Misc.php
+++ b/src/Helper/Helper_Misc.php
@@ -788,7 +788,7 @@ public function get_legacy_ids( $entry_id, $settings ) {
 	 * @deprecated 6.12 compatibility code no longer required
 	 */
 	public function maybe_add_multicurrency_support() {
-		_doing_it_wrong( __METHOD__, 'This method has been removed and no alternative is available.', '6.12' );
+		_deprecated_function( __METHOD__, '6.12' );
 	}
 
 	/**
diff --git a/src/Helper/Helper_Notices.php b/src/Helper/Helper_Notices.php
index 6c6210ebf..58180865a 100644
--- a/src/Helper/Helper_Notices.php
+++ b/src/Helper/Helper_Notices.php
@@ -61,7 +61,9 @@ public function add_actions(): void {
 	 * @since 6.5
 	 * @deprecated 6.11 No longer required. Running all notices through standard WP hooks, but have included `gf-notice` class so GF does not remove it
 	 */
-	public function maybe_remove_non_pdf_messages(): void {}
+	public function maybe_remove_non_pdf_messages(): void {
+		_deprecated_function( __METHOD__, '6.11' );
+	}
 
 	/**
 	 * Determine which notice should be triggered
@@ -80,32 +82,32 @@ protected function get_notice_type(): string {
 	 * Public endpoint for adding a new notice
 	 *
 	 * @param string $notice    The message to be queued
-	 * @param string $css_class The class that should be included with the notice box
+	 * @param string $css_class The class that should be included with the notice box. Pass a WordPress `notice-*`
+	 *                          state class, like `notice-warning`, to override the default success styling.
 	 *
 	 * @since 4.0
 	 */
 	public function add_notice( $notice, $css_class = '' ): void {
-		if ( empty( $css_class ) ) {
-			$this->notices[] = $notice;
-		} else {
-			$this->notices[ $css_class ] = $notice;
-		}
+		$this->notices[] = [
+			'message' => $notice,
+			'class'   => $css_class,
+		];
 	}
 
 	/**
 	 * Public endpoint for adding a new notice
 	 *
 	 * @param string $error     The error message that should be added
-	 * @param string $css_class Any class names that should apply to the error
+	 * @param string $css_class Any class names that should apply to the error, including a WordPress `notice-*`
+	 *                          state class to override the default error styling
 	 *
 	 * @since    4.0
 	 */
 	public function add_error( $error, $css_class = '' ) {
-		if ( empty( $css_class ) ) {
-			$this->errors[] = $error;
-		} else {
-			$this->errors[ $css_class ] = $error;
-		}
+		$this->errors[] = [
+			'message' => $error,
+			'class'   => $css_class,
+		];
 	}
 
 	/**
@@ -154,26 +156,26 @@ public function process(): void {
 			return;
 		}
 
-		foreach ( $this->notices as $css_class => $notice ) {
-			$include_class = ( ! is_int( $css_class ) ) ? $css_class : '';
-			$this->html( $notice, 'updated ' . $include_class );
+		foreach ( $this->notices as $notice ) {
+			$this->html( $notice['message'], $notice['class'], 'updated' );
 		}
 
-		foreach ( $this->errors as $css_class => $error ) {
-			$include_class = ( ! is_int( $css_class ) ) ? $css_class : '';
-			$this->html( $error, 'error ' . $include_class );
+		foreach ( $this->errors as $error ) {
+			$this->html( $error['message'], $error['class'], 'error' );
 		}
 	}
 
 	/**
 	 * Generate the HTML used to display the notice / error
 	 *
-	 * @param string $text      The message to be displayed
-	 * @param string $css_class The class name (updated / error)
+	 * @param string $text          The message to be displayed
+	 * @param string $css_class     Any classes the caller asked for
+	 * @param string $default_state The state class used when the caller hasn't chosen one (updated / error)
 	 *
 	 * @since 4.0
+	 * @since 6.17.0 Added $default_state
 	 */
-	protected function html( string $text, string $css_class = 'updated' ): void {
+	protected function html( string $text, string $css_class = '', string $default_state = 'updated' ): void {
 		$allow_form_elements = static function ( $tags ) {
 			$tags['input'] = [
 				'type'  => true,
@@ -187,12 +189,16 @@ protected function html( string $text, string $css_class = 'updated' ): void {
 
 		add_filter( 'wp_kses_allowed_html', $allow_form_elements );
 
+		/* `div.updated` out-specifies `.notice-warning`, so a caller-supplied state replaces ours instead of joining it */
+		$state   = strpos( $css_class, 'notice-' ) === false ? $default_state : '';
+		$classes = trim( $state . ' ' . $css_class );
+
 		/* Add specific classes on Gravity Forms page so the notice displays correctly */
 		if ( class_exists( 'GFForms' ) && \GFForms::is_gravity_page() ) {
-			$classes  = 'notice gf-notice gform-settings__wrapper ' . $css_class;
-			$classes .= strpos( $css_class, 'updated' ) !== false ? ' notice-success' : '';
+			$classes  = 'notice gf-notice gform-settings__wrapper ' . $classes;
+			$classes .= $state === 'updated' ? ' notice-success' : '';
 		} else {
-			$classes = 'notice ' . $css_class;
+			$classes = 'notice ' . $classes;
 		}
 
 		?>
@@ -214,8 +220,9 @@ protected function html( string $text, string $css_class = 'updated' ): void {
 	 * @return bool
 	 *
 	 * @since 6.11
+	 * @since 6.17.0 Made public so callers can skip building a notice that would be discarded
 	 */
-	protected function can_display_notice_on_this_page() {
+	public function can_display_notice_on_this_page() {
 		global $pagenow;
 
 		$misc = \GPDFAPI::get_misc_class();
@@ -251,6 +258,8 @@ protected function can_display_notice_on_this_page() {
 	 * @deprecated 6.11 No longer required. Running all notices through standard WP hooks, but have included `gf-notice` class so GF does not remove it
 	 */
 	public function reset_gravityforms_messages( $messages ) {
+		_deprecated_function( __METHOD__, '6.11' );
+
 		return $messages;
 	}
 
@@ -265,6 +274,8 @@ public function reset_gravityforms_messages( $messages ) {
 	 * @deprecated 6.11 No longer required. Running all notices through standard WP hooks, but have included `gf-notice` class so GF does not remove it
 	 */
 	public function set_gravitypdf_notices( $messages ) {
+		_deprecated_function( __METHOD__, '6.11' );
+
 		return $messages;
 	}
 
@@ -279,6 +290,8 @@ public function set_gravitypdf_notices( $messages ) {
 	 * @deprecated 6.11 No longer required. Running all notices through standard WP hooks, but have included `gf-notice` class so GF does not remove it
 	 */
 	public function set_gravitypdf_errors( $errors ) {
+		_deprecated_function( __METHOD__, '6.11' );
+
 		return $errors;
 	}
 }
diff --git a/src/Helper/Helper_Options_Fields.php b/src/Helper/Helper_Options_Fields.php
index 07a3eb1cf..b24d1275b 100644
--- a/src/Helper/Helper_Options_Fields.php
+++ b/src/Helper/Helper_Options_Fields.php
@@ -2,6 +2,7 @@
 
 namespace GFPDF\Helper;
 
+use GFPDF\Statics\Deprecation;
 use WP_Error;
 
 /**
@@ -693,11 +694,11 @@ public function get_registered_fields() {
 	 */
 	public function get_advanced_template_field( $settings ) {
 
-		if ( ! class_exists( 'gfpdfe_business_plus' ) ) {
+		if ( ! Deprecation::has_tier_2_addon() ) {
 			return $settings;
 		}
 
-		_doing_it_wrong( __METHOD__, 'Legacy templates are deprecated and no longer supported. Contact GravityPDF.com to discuss upgrade options.', '6.12' );
+		_deprecated_function( __METHOD__, '6.12', 'a Gravity PDF 6 template, https://docs.gravitypdf.com/developers/upgrade-legacy-template/' );
 
 		$settings['advanced_template'] = [
 			'id'   => 'advanced_template',
diff --git a/src/Helper/Helper_PDF.php b/src/Helper/Helper_PDF.php
index 4ae0666c4..b385a9d19 100644
--- a/src/Helper/Helper_PDF.php
+++ b/src/Helper/Helper_PDF.php
@@ -5,6 +5,7 @@
 use Exception;
 use GFPDF\Helper\Mpdf\Request;
 use GFPDF\Statics\Cache;
+use GFPDF\Statics\Deprecation;
 use GFPDF_Vendor\Mpdf\Config\FontVariables;
 use GFPDF\Helper\Mpdf\Mpdf;
 use GFPDF_Vendor\Mpdf\MpdfException;
@@ -266,8 +267,8 @@ public function render_html( $args = [], $html = '' ) {
 		}
 
 		/* Apply our filters */
-		$html = apply_filters( 'gfpdfe_pdf_template', $html, $form['id'], $this->entry['id'], $args['settings'] ); /* Backwards compat */
-		$html = apply_filters( 'gfpdfe_pdf_template_' . $form['id'], $html, $this->entry['id'], $args['settings'] ); /* Backwards compat */
+		$html = Deprecation::apply_filters( 'gfpdfe_pdf_template', [ $html, $form['id'], $this->entry['id'], $args['settings'] ] );
+		$html = Deprecation::apply_filters( 'gfpdfe_pdf_template_' . $form['id'], [ $html, $this->entry['id'], $args['settings'] ], 'gfpdf_pdf_html_output_' . $form['id'] );
 
 		/* See https://docs.gravitypdf.com/developers/filters/gfpdf_pdf_html_output/ for more details about these filters */
 		$html = apply_filters( 'gfpdf_pdf_html_output', $html, $form, $this->entry, $args['settings'], $this );
@@ -302,9 +303,11 @@ public function generate() {
 		$this->mpdf = apply_filters( 'gfpdf_mpdf_class', $this->mpdf, $form, $this->entry, $this->settings, $this );
 
 		/* deprecated backwards compatibility filters */
-		$this->mpdf = apply_filters( 'gfpdfe_mpdf_class_pre_render', $this->mpdf, $this->entry['form_id'], $this->entry['id'], $this->settings, '', $this->get_filename() );
-		$this->mpdf = apply_filters( 'gfpdfe_pre_render_pdf', $this->mpdf, $this->entry['form_id'], $this->entry['id'], $this->settings, '', $this->get_filename() );
-		$this->mpdf = apply_filters( 'gfpdfe_mpdf_class', $this->mpdf, $this->entry['form_id'], $this->entry['id'], $this->settings, '', $this->get_filename() );
+		$legacy_args = [ $this->entry['form_id'], $this->entry['id'], $this->settings, '', $this->get_filename() ];
+
+		$this->mpdf = Deprecation::apply_filters( 'gfpdfe_mpdf_class_pre_render', array_merge( [ $this->mpdf ], $legacy_args ) );
+		$this->mpdf = Deprecation::apply_filters( 'gfpdfe_pre_render_pdf', array_merge( [ $this->mpdf ], $legacy_args ) );
+		$this->mpdf = Deprecation::apply_filters( 'gfpdfe_mpdf_class', array_merge( [ $this->mpdf ], $legacy_args ) );
 
 		do_action( 'gfpdf_pre_pdf_generation_output', $this->mpdf, $form, $this->entry, $this->settings, $this );
 
diff --git a/src/Helper/Helper_Templates.php b/src/Helper/Helper_Templates.php
index 7a86d4722..88f171139 100644
--- a/src/Helper/Helper_Templates.php
+++ b/src/Helper/Helper_Templates.php
@@ -3,6 +3,7 @@
 namespace GFPDF\Helper;
 
 use Exception;
+use GFPDF\Statics\Deprecation;
 use GPDFAPI;
 use GFPDF_Vendor\Psr\Log\LoggerInterface;
 use stdClass;
@@ -273,6 +274,19 @@ function ( $template_path ) {
 		);
 	}
 
+	/**
+	 * Check if the template info describes a legacy (v3) template
+	 *
+	 * A v3 template has no `Group` header, so self::get_template_info_by_path() falls back to the Legacy group.
+	 *
+	 * @param array $info The template header info
+	 *
+	 * @since 6.17.0
+	 */
+	public function is_legacy_template( array $info ): bool {
+		return ( $info['group'] ?? '' ) === esc_html__( 'Legacy', 'gravity-pdf' );
+	}
+
 	/**
 	 * Get the PDF template path by the template name
 	 *
@@ -766,7 +780,7 @@ public function get_template_arguments( $form, $fields, $entry, $form_data, $set
 
 				'form_id'   => $form['id'], /* backwards compat */
 				'lead_ids'  => $legacy_ids, /* backwards compat */
-				'lead_id'   => apply_filters( 'gfpdfe_lead_id', $entry['id'], $form, $entry, $gfpdf ), /* backwards compat */
+				'lead_id'   => Deprecation::apply_filters( 'gfpdfe_lead_id', [ $entry['id'], $form, $entry, $gfpdf ] ), /* backwards compat */
 
 				'form'      => $form,
 				'entry'     => $entry,
diff --git a/src/Model/Model_Install.php b/src/Model/Model_Install.php
index e9d82a641..ceb087b5d 100644
--- a/src/Model/Model_Install.php
+++ b/src/Model/Model_Install.php
@@ -10,6 +10,7 @@
 use GFPDF\Helper\Helper_Misc;
 use GFPDF\Helper\Helper_Notices;
 use GFPDF\Helper\Helper_Pdf_Queue;
+use GFPDF\Statics\Deprecation;
 use GFPDF_Vendor\Psr\Log\LoggerInterface;
 
 /**
@@ -182,8 +183,8 @@ public function setup_template_location() {
 		$upload_dir_url = $this->data->upload_dir_url;
 
 		/* Legacy Filters */
-		$this->data->template_location     = trailingslashit( apply_filters( 'gfpdfe_template_location', $template_dir, $working_folder, $upload_dir ) );
-		$this->data->template_location_url = trailingslashit( apply_filters( 'gfpdfe_template_location_uri', $template_url, $working_folder, $upload_dir_url ) );
+		$this->data->template_location     = trailingslashit( Deprecation::apply_filters( 'gfpdfe_template_location', [ $template_dir, $working_folder, $upload_dir ] ) );
+		$this->data->template_location_url = trailingslashit( Deprecation::apply_filters( 'gfpdfe_template_location_uri', [ $template_url, $working_folder, $upload_dir_url ] ) );
 
 		/* Allow user to change directory location(s) */
 
@@ -398,6 +399,8 @@ public function maybe_flush_rewrite_rules( $regex ) {
 	 * @since 4.0
 	 */
 	public function uninstall_plugin() {
+		_deprecated_function( __METHOD__, '6.0', 'Model_Uninstall::uninstall_plugin()' );
+
 		$this->uninstall->uninstall_plugin();
 	}
 
@@ -409,6 +412,8 @@ public function uninstall_plugin() {
 	 * @since 4.0
 	 */
 	public function remove_plugin_options() {
+		_deprecated_function( __METHOD__, '6.0', 'Model_Uninstall::remove_plugin_options()' );
+
 		$this->uninstall->remove_plugin_options();
 	}
 
@@ -421,6 +426,8 @@ public function remove_plugin_options() {
 	 * @since 4.0
 	 */
 	public function remove_plugin_form_settings() {
+		_deprecated_function( __METHOD__, '6.0', 'Model_Uninstall::remove_plugin_form_settings()' );
+
 		$this->uninstall->remove_plugin_form_settings();
 	}
 
@@ -432,6 +439,8 @@ public function remove_plugin_form_settings() {
 	 * @since 4.0
 	 */
 	public function remove_folder_structure() {
+		_deprecated_function( __METHOD__, '6.0', 'Model_Uninstall::remove_folder_structure()' );
+
 		$this->uninstall->remove_folder_structure();
 	}
 
@@ -443,6 +452,8 @@ public function remove_folder_structure() {
 	 * @since 4.0
 	 */
 	public function deactivate_plugin() {
+		_deprecated_function( __METHOD__, '6.0', 'Model_Uninstall::deactivate_plugin()' );
+
 		$this->uninstall->deactivate_plugin();
 	}
 
diff --git a/src/Model/Model_PDF.php b/src/Model/Model_PDF.php
index 308901bd6..a040318cd 100644
--- a/src/Model/Model_PDF.php
+++ b/src/Model/Model_PDF.php
@@ -23,6 +23,7 @@
 use GFPDF\Helper\Helper_Options_Fields;
 use GFPDF\Helper\Helper_PDF;
 use GFPDF\Helper\Helper_Templates;
+use GFPDF\Statics\Deprecation;
 use GFPDF_Vendor\Mpdf\Mpdf;
 use GFPDF_Vendor\Spatie\UrlSigner\Exceptions\InvalidSignatureKey;
 use GFQuiz;
@@ -246,7 +247,7 @@ public function process_pdf( $pid, $lid, $action = 'view' ) {
 		 * To prevent cache misses we need to ensure we don't unnecessarily modify the settings array
 		 */
 		unset( $settings['pdf_action'] );
-		$action = apply_filters( 'gfpdfe_pdf_output_type', $action ); /* Backwards compat */
+		$action = Deprecation::apply_filters( 'gfpdfe_pdf_output_type', [ $action ] );
 		$action = in_array( $action, [ 'view', 'download' ], true ) ? $action : 'view';
 
 		/* Get the PDF document for the request */
@@ -290,31 +291,31 @@ public function apply_backwards_compatibility_filters( $settings, $entry ) {
 
 		$form = apply_filters( 'gfpdf_current_form_object', $this->gform->get_form( $entry['form_id'] ), $entry, __FUNCTION__ );
 
-		$settings['filename'] = $this->misc->remove_extension_from_string( apply_filters( 'gfpdfe_pdf_name', $settings['filename'], $form, $entry ) );
-		$settings['template'] = $this->misc->remove_extension_from_string( apply_filters( 'gfpdfe_template', $settings['template'], $form, $entry ), '.php' );
+		$settings['filename'] = $this->misc->remove_extension_from_string( Deprecation::apply_filters( 'gfpdfe_pdf_name', [ $settings['filename'], $form, $entry ] ) );
+		$settings['template'] = $this->misc->remove_extension_from_string( Deprecation::apply_filters( 'gfpdfe_template', [ $settings['template'], $form, $entry ] ), '.php' );
 
 		if ( isset( $settings['orientation'] ) ) {
-			$settings['orientation'] = apply_filters( 'gfpdf_orientation', $settings['orientation'], $form, $entry );
+			$settings['orientation'] = Deprecation::apply_filters( 'gfpdf_orientation', [ $settings['orientation'], $form, $entry ] );
 		}
 
 		if ( isset( $settings['security'] ) ) {
-			$settings['security'] = $this->misc->update_deprecated_config( apply_filters( 'gfpdf_security', $settings['security'], $form, $entry ) );
+			$settings['security'] = $this->misc->update_deprecated_config( Deprecation::apply_filters( 'gfpdf_security', [ $settings['security'], $form, $entry ] ) );
 		}
 
 		if ( isset( $settings['privileges'] ) ) {
-			$settings['privileges'] = apply_filters( 'gfpdf_privilages', $settings['privileges'], $form, $entry );
+			$settings['privileges'] = Deprecation::apply_filters( 'gfpdf_privilages', [ $settings['privileges'], $form, $entry ] );
 		}
 
 		if ( isset( $settings['password'] ) ) {
-			$settings['password'] = apply_filters( 'gfpdf_password', $settings['password'], $form, $entry );
+			$settings['password'] = Deprecation::apply_filters( 'gfpdf_password', [ $settings['password'], $form, $entry ] );
 		}
 
 		if ( isset( $settings['master_password'] ) ) {
-			$settings['master_password'] = apply_filters( 'gfpdf_master_password', $settings['master_password'], $form, $entry );
+			$settings['master_password'] = Deprecation::apply_filters( 'gfpdf_master_password', [ $settings['master_password'], $form, $entry ] );
 		}
 
 		if ( isset( $settings['rtl'] ) ) {
-			$settings['rtl'] = $this->misc->update_deprecated_config( apply_filters( 'gfpdf_rtl', $settings['rtl'], $form, $entry ) );
+			$settings['rtl'] = $this->misc->update_deprecated_config( Deprecation::apply_filters( 'gfpdf_rtl', [ $settings['rtl'], $form, $entry ] ) );
 		}
 
 		return $settings;
@@ -865,7 +866,7 @@ public function get_pdf_name( $settings, $entry ) {
 		$name = apply_filters( 'gfpdf_pdf_filename', $name, $form, $entry, $settings );
 
 		/* Backwards compatible filter */
-		$name = apply_filters( 'gfpdfe_pdf_filename', $name, $form, $entry, $settings );
+		$name = Deprecation::apply_filters( 'gfpdfe_pdf_filename', [ $name, $form, $entry, $settings ] );
 
 		/* Remove any characters that cannot be present in a filename */
 		$name = $this->misc->strip_invalid_characters( $name );
@@ -890,7 +891,7 @@ public function get_pdf_url( $pid, $id, $download = false, $should_print = false
 		global $wp_rewrite;
 
 		if ( $esc !== true ) {
-			_doing_it_wrong( __METHOD__, '$esc has been deprecated. Late-escape the returned value where appropriate.', '6.4.0' );
+			_deprecated_argument( __METHOD__, '6.4.0', 'The $esc argument is ignored. Late-escape the returned value where appropriate.' );
 		}
 
 		/*
@@ -1455,17 +1456,21 @@ public function handle_legacy_tier_2_processing( Helper_PDF $pdf_generator, $ent
 
 		$form = apply_filters( 'gfpdf_current_form_object', $this->gform->get_form( $entry['form_id'] ), $entry, __FUNCTION__ );
 
-		$prevent_main_pdf_loader = apply_filters(
+		$this->log->warning( sprintf( 'Advanced Templating (Tier 2) processing is removed in Gravity PDF %s. Contact GravityPDF.com to discuss upgrade options.', Deprecation::REMOVED_IN ) );
+
+		$prevent_main_pdf_loader = Deprecation::apply_filters(
 			'gfpdfe_pre_load_template',
-			$form['id'],
-			$entry['id'],
-			basename( $pdf_generator->get_template_path() ),
-			$form['id'] . $entry['id'],
-			$this->misc->backwards_compat_output( $pdf_generator->get_output_type() ),
-			$pdf_generator->get_filename(),
-			$this->misc->backwards_compat_conversion( $settings, $form, $entry ),
-			$args
-		); /* Backwards Compatibility */
+			[
+				$form['id'],
+				$entry['id'],
+				basename( $pdf_generator->get_template_path() ),
+				$form['id'] . $entry['id'],
+				$this->misc->backwards_compat_output( $pdf_generator->get_output_type() ),
+				$pdf_generator->get_filename(),
+				$this->misc->backwards_compat_conversion( $settings, $form, $entry ),
+				$args,
+			]
+		);
 
 		return $prevent_main_pdf_loader === true;
 	}
@@ -2045,7 +2050,7 @@ public function cleanup_tmp_dir() {
 	 * @deprecated 6.12 Caching layer + auto-purge added
 	 */
 	public function cleanup_pdf_after_submission( $form, $entry_id ) {
-		_doing_it_wrong( __METHOD__, 'This method is deprecated and no alternative is available. The temporary cache is automatically cleaned every hour using the WP Cron.', '6.12' );
+		_deprecated_function( __METHOD__, '6.12' );
 
 		/* Exit if background processing is enabled */
 		if ( $this->options->get_option( 'background_processing', 'No' ) === 'Yes' ) {
@@ -2076,7 +2081,7 @@ public function cleanup_pdf_after_submission( $form, $entry_id ) {
 	 * @deprecated 6.12 Caching layer + auto-purge added
 	 */
 	public function cleanup_pdf( $entry, $form ) {
-		_doing_it_wrong( __METHOD__, 'This method is deprecated and no alternative is available. The temporary cache is automatically cleaned every hour using the WP Cron.', '6.12' );
+		_deprecated_function( __METHOD__, '6.12' );
 
 		$pdfs = $this->get_active_pdfs( $form['gfpdf_form_settings'] ?? [], $entry );
 
@@ -2112,7 +2117,7 @@ public function cleanup_pdf( $entry, $form ) {
 	 * @deprecated 6.12 Caching layer + auto-purge added
 	 */
 	public function resend_notification_pdf_cleanup( $form, $entries ) {
-		_doing_it_wrong( __METHOD__, 'This method is deprecated and no alternative is available. The temporary cache is automatically cleaned every hour using the WP Cron.', '6.12' );
+		_deprecated_function( __METHOD__, '6.12' );
 
 		foreach ( $entries as $entry_id ) {
 			$entry = $this->gform->get_entry( $entry_id );
@@ -2227,7 +2232,7 @@ function ( $val ) use ( &$flattened_fonts_array ) {
 	 * @deprecated 4.0 Added for backwards compatibility, but ideally should not be used
 	 */
 	public function get_legacy_config( $config ) {
-		_doing_it_wrong( __METHOD__, 'Legacy PDF URLs are deprecated. Replace with the [gravitypdf] shortcode or PDF merge tags. See https://docs.gravitypdf.com/v6/users/shortcodes-and-mergetags for usage instructions.', '4.0' );
+		_deprecated_function( __METHOD__, '4.0', 'the [gravitypdf] shortcode or PDF merge tags, https://docs.gravitypdf.com/v6/users/shortcodes-and-mergetags' );
 
 		/* Get the form settings */
 		$pdfs = $this->options->get_form_pdfs( $config['fid'] );
diff --git a/src/Model/Model_Settings.php b/src/Model/Model_Settings.php
index 335b3c014..b2b391c89 100644
--- a/src/Model/Model_Settings.php
+++ b/src/Model/Model_Settings.php
@@ -720,7 +720,9 @@ public function deactivate_license_key( Helper_Abstract_Addon $addon, $license_k
 	 *
 	 * @deprecated Removed in 6.0. Use GPDFAPI::delete_pdf_font()
 	 */
-	public function remove_font_file( $fonts ) {}
+	public function remove_font_file( $fonts ) {
+		_deprecated_function( __METHOD__, '6.0', 'GPDFAPI::delete_pdf_font()' );
+	}
 
 	/**
 	 * Check that the font name passed conforms to our expected naming convention
@@ -731,7 +733,9 @@ public function remove_font_file( $fonts ) {}
 	 *
 	 * @deprecated Moved in 6.0. Use Model_Custom_Fonts::check_font_name_valid()
 	 */
-	public function is_font_name_valid( $name ) {}
+	public function is_font_name_valid( $name ) {
+		_deprecated_function( __METHOD__, '6.0', 'Model_Custom_Fonts::check_font_name_valid()' );
+	}
 
 	/**
 	 * Query our custom fonts options table and check if the font name already exists
@@ -743,7 +747,9 @@ public function is_font_name_valid( $name ) {}
 	 *
 	 * @deprecated Removed in 6.0. Font names no longer need to be unique
 	 */
-	public function is_font_name_unique( $name, $id = '' ) {}
+	public function is_font_name_unique( $name, $id = '' ) {
+		_deprecated_function( __METHOD__, '6.0' );
+	}
 
 	/**
 	 * Handles the database updates required to save a new font
@@ -754,7 +760,9 @@ public function is_font_name_unique( $name, $id = '' ) {}
 	 *
 	 * @deprecated Moved in 6.0 to Model_Custom_Fonts::add_font()
 	 */
-	public function install_fonts( $fonts ) {}
+	public function install_fonts( $fonts ) {
+		_deprecated_function( __METHOD__, '6.0', 'Model_Custom_Fonts::add_font()' );
+	}
 
 	/**
 	 * AJAX Endpoint for saving the custom font
@@ -763,7 +771,9 @@ public function install_fonts( $fonts ) {}
 	 *
 	 * @deprecated Moved in 6.0. Use GPDFAPI::add_pdf_font()
 	 */
-	public function save_font() {}
+	public function save_font() {
+		_deprecated_function( __METHOD__, '6.0', 'GPDFAPI::add_pdf_font()' );
+	}
 
 	/**
 	 * AJAX Endpoint for deleting a custom font
@@ -772,7 +782,9 @@ public function save_font() {}
 	 *
 	 * @deprecated Moved in 6.0. Use GPDFAPI::delete_pdf_font()
 	 */
-	public function delete_font() {}
+	public function delete_font() {
+		_deprecated_function( __METHOD__, '6.0', 'GPDFAPI::delete_pdf_font()' );
+	}
 
 	/**
 	 * Validate user input and save as new font
@@ -783,7 +795,9 @@ public function delete_font() {}
 	 *
 	 * @deprecated Removed in 6.0. Use GPDFAPI::add_pdf_font()
 	 */
-	public function process_font( $font ) {}
+	public function process_font( $font ) {
+		_deprecated_function( __METHOD__, '6.0', 'GPDFAPI::add_pdf_font()' );
+	}
 
 	/**
 	 * Find the font unique ID from the font name
@@ -794,7 +808,9 @@ public function process_font( $font ) {}
 	 *
 	 * @deprecated Removed in 6.0. Font names no longer linked to IDs.
 	 */
-	public function get_font_id_by_name( $font_name ) {}
+	public function get_font_id_by_name( $font_name ) {
+		_deprecated_function( __METHOD__, '6.0' );
+	}
 
 	/**
 	 * Create a file in our tmp directory and check if it is publicly accessible (i.e no .htaccess protection)
@@ -803,7 +819,9 @@ public function get_font_id_by_name( $font_name ) {}
 	 *
 	 * @deprecated Functionality removed in 6.0
 	 */
-	public function check_tmp_pdf_security() {}
+	public function check_tmp_pdf_security() {
+		_deprecated_function( __METHOD__, '6.0' );
+	}
 
 	/**
 	 * Create a file in our tmp directory and verify if it's protected from the public
@@ -815,6 +833,8 @@ public function check_tmp_pdf_security() {}
 	 * @deprecated Moved in 6.0. Use Model_System_Report::test_public_tmp_directory_access()
 	 */
 	public function test_public_tmp_directory_access() {
+		_deprecated_function( __METHOD__, '6.0', 'Model_System_Report::test_public_tmp_directory_access()' );
+
 		/** @var Model_System_Report $model_system_report */
 		$model_system_report = \GPDFAPI::get_mvc_class( 'Model_System_Report' );
 
diff --git a/src/Model/Model_Shortcodes.php b/src/Model/Model_Shortcodes.php
index ecfcb8b7b..3927d9b83 100644
--- a/src/Model/Model_Shortcodes.php
+++ b/src/Model/Model_Shortcodes.php
@@ -47,7 +47,7 @@ class Model_Shortcodes extends Helper_Abstract_Pdf_Shortcode {
 	 * @internal Deprecated in 5.2. Use Model_Shortcodes::process()
 	 */
 	public function gravitypdf( $attributes ) {
-		_doing_it_wrong( __METHOD__, 'This method has been replaced by Model_Shortcodes::process()', '5.2' );
+		_deprecated_function( __METHOD__, '5.2', 'Model_Shortcodes::process()' );
 
 		return $this->process( $attributes );
 	}
diff --git a/src/Model/Model_System_Report.php b/src/Model/Model_System_Report.php
index 826478c9a..5bcede73c 100644
--- a/src/Model/Model_System_Report.php
+++ b/src/Model/Model_System_Report.php
@@ -9,6 +9,7 @@
 use GFPDF\Helper\Helper_Data;
 use GFPDF\Helper\Helper_Misc;
 use GFPDF\Helper\Helper_Templates;
+use GFPDF\Statics\Deprecation;
 use GFPDF_Major_Compatibility_Checks;
 use GFPDF_Vendor\Psr\Log\LoggerInterface;
 
@@ -96,6 +97,14 @@ public function build_gravitypdf_report(): array {
 			}
 		}
 
+		/* Drop any section with nothing to show, which is how Deprecated Features stays hidden on a clean site */
+		$structure[0]['tables'] = array_filter(
+			$structure[0]['tables'],
+			static function ( $table ) {
+				return ! empty( $table['items'] );
+			}
+		);
+
 		return $structure;
 	}
 
@@ -134,6 +143,12 @@ public function get_report_structure(): array {
 						'title_export' => $title_export_prefix . 'Security Settings',
 						'items'        => [],
 					],
+
+					[
+						'title'        => esc_html__( 'Deprecated Features', 'gravity-pdf' ),
+						'title_export' => $title_export_prefix . 'Deprecated Features',
+						'items'        => [],
+					],
 				],
 			],
 		];
@@ -246,7 +261,7 @@ protected function get_report_items(): array {
 			],
 		];
 
-		/* Check if outdated core template overrides and display warning */
+		/* Check for outdated core template overrides and display a warning */
 		$template_status = $this->check_core_template_override_versions();
 		if ( ! empty( $template_status ) ) {
 			$items[1]['outdated_templates'] = [
@@ -315,9 +330,56 @@ protected function get_report_items(): array {
 			],
 		];
 
+		/* Deprecated Features */
+		$items[] = $this->get_deprecated_feature_items();
+
 		return apply_filters( 'gfpdf_system_status_report_items', $items );
 	}
 
+	/**
+	 * Build the rows for the Deprecated Features section
+	 *
+	 * Each row is only included when that feature is actually in use on this site, and the section itself is
+	 * discarded by build_gravitypdf_report() when nothing is detected.
+	 *
+	 * @since 6.17.0
+	 */
+	protected function get_deprecated_feature_items(): array {
+		$view   = $this->getController()->view;
+		$labels = Deprecation::get_feature_labels();
+
+		$items = [];
+		foreach ( $this->get_deprecated_signals() as $key => $signal ) {
+			$items[ $key ] = [
+				'label'        => esc_html( $labels[ $key ] ),
+				'label_export' => $labels[ $key ],
+			] + $view->get_deprecated_feature_message( $key, $signal );
+		}
+
+		return $items;
+	}
+
+	/**
+	 * Get the deprecated functionality in use on this site, ready to display
+	 *
+	 * @since 6.17.0
+	 */
+	public function get_deprecated_signals(): array {
+		$signals = Deprecation::get_signals( true );
+
+		/* Show template paths relative to the WordPress root, as the rest of the report does */
+		if ( isset( $signals['legacy_templates'] ) ) {
+			$signals['legacy_templates'] = array_map(
+				function ( $path ) {
+					return $this->misc->relative_path( $path, '/' );
+				},
+				$signals['legacy_templates']
+			);
+		}
+
+		return $signals;
+	}
+
 	/**
 	 * Returns text and dashicon for Memory Limit
 	 *
@@ -446,7 +508,7 @@ protected function check_core_template_override_versions(): array {
 		foreach ( $templates as $path => $core_version ) {
 			$template = $this->templates->get_template_info_by_id( basename( $path, '.php' ) );
 			if ( version_compare( $core_version, $template['version'], '>' ) ) {
-				$relative_template_path = str_replace( ABSPATH, '/', $template['path'] );
+				$relative_template_path = $this->misc->relative_path( $template['path'], '/' );
 				$message                = $this->getController()->view->get_template_check_message( $relative_template_path, $template['version'], $core_version );
 
 				$value        .= $message['value'];
diff --git a/src/Model/Model_Templates.php b/src/Model/Model_Templates.php
index 3c84324b1..f0cbd5635 100644
--- a/src/Model/Model_Templates.php
+++ b/src/Model/Model_Templates.php
@@ -391,7 +391,7 @@ public function check_for_valid_pdf_templates( $files = [] ) {
 			/* Check if we have a valid v4 template header in the file */
 			$info = $this->templates->get_template_info_by_path( $file );
 
-			if ( $info['group'] === esc_html__( 'Legacy', 'gravity-pdf' ) ) {
+			if ( $this->templates->is_legacy_template( $info ) ) {
 				/* Check if it's a v3 template */
 				$fp        = fopen( $file, 'rb' );
 				$file_data = fread( $fp, 8192 );
diff --git a/src/Statics/Deprecation.php b/src/Statics/Deprecation.php
new file mode 100644
index 000000000..f103d47cc
--- /dev/null
+++ b/src/Statics/Deprecation.php
@@ -0,0 +1,418 @@
+<?php
+
+declare( strict_types=1 );
+
+namespace GFPDF\Statics;
+
+/**
+ * @package     Gravity PDF
+ * @copyright   Copyright (c) 2026, Blue Liquid Designs
+ * @license     http://opensource.org/licenses/gpl-2.0.php GNU Public License
+ */
+
+/* Exit if accessed directly */
+if ( ! defined( 'ABSPATH' ) ) {
+	exit;
+}
+
+/**
+ * Detects and records use of the v3 backwards compatibility layer scheduled for removal in Gravity PDF 7.0
+ *
+ * @since 6.17.0
+ */
+class Deprecation {
+
+	/**
+	 * The release the v3 backwards compatibility layer is removed in
+	 *
+	 * @var string
+	 * @since 6.17.0
+	 */
+	const REMOVED_IN = '7.0';
+
+	/**
+	 * Option key recording use of the legacy `?gf_pdf=` PDF endpoint
+	 *
+	 * @var string
+	 * @since 6.17.0
+	 */
+	const ENDPOINT_USAGE_OPTION = 'gfpdf_legacy_endpoint_usage';
+
+	/**
+	 * Transient key caching the results of the filesystem/database signal scans
+	 *
+	 * @var string
+	 * @since 6.17.0
+	 */
+	const SIGNAL_CACHE_KEY = 'gfpdf_deprecation_signals';
+
+	/**
+	 * How many distinct form IDs the legacy endpoint recorder will store
+	 *
+	 * @var int
+	 * @since 6.17.0
+	 */
+	const MAX_RECORDED_FORMS = 20;
+
+	/**
+	 * The `gfpdfe_pre_load_template` callback core registers itself, which the listener scan must ignore
+	 *
+	 * @var array
+	 * @since 6.17.0
+	 */
+	const INTERNAL_FILTER_CALLBACK = [ 'PDFRender', 'prepare_ids' ];
+
+	/**
+	 * The deprecated v3 filters still fired by core, mapped to their v4+ replacement
+	 *
+	 * An empty replacement means no equivalent exists.
+	 *
+	 * @return array<string, string>
+	 * @since 6.17.0
+	 */
+	public static function get_deprecated_filters(): array {
+		return [
+			'gfpdfe_template_location'     => 'gfpdf_template_location',
+			'gfpdfe_template_location_uri' => 'gfpdf_template_location_uri',
+			'gfpdfe_pdf_output_type'       => '',
+			'gfpdfe_pdf_name'              => 'gfpdf_pdf_config',
+			'gfpdfe_template'              => 'gfpdf_pdf_config',
+			'gfpdfe_pdf_filename'          => 'gfpdf_pdf_filename',
+			'gfpdfe_pdf_template'          => 'gfpdf_pdf_html_output',
+			'gfpdfe_mpdf_class_pre_render' => 'gfpdf_mpdf_class',
+			'gfpdfe_pre_render_pdf'        => 'gfpdf_mpdf_class',
+			'gfpdfe_mpdf_class'            => 'gfpdf_mpdf_class',
+			'gfpdfe_lead_id'               => 'gfpdf_template_args',
+			'gfpdfe_signature_width'       => 'gfpdf_signature_width',
+			'gfpdfe_pre_load_template'     => '',
+			'gfpdf_orientation'            => 'gfpdf_pdf_config',
+			'gfpdf_security'               => 'gfpdf_pdf_config',
+			'gfpdf_privilages'             => 'gfpdf_pdf_config',
+			'gfpdf_password'               => 'gfpdf_pdf_config',
+			'gfpdf_master_password'        => 'gfpdf_pdf_config',
+			'gfpdf_rtl'                    => 'gfpdf_pdf_config',
+		];
+	}
+
+	/**
+	 * The signals returned by self::get_signals(), mapped to how they are named to the user
+	 *
+	 * @return array<string, string>
+	 * @since 6.17.0
+	 */
+	public static function get_feature_labels(): array {
+		return [
+			'legacy_templates'   => __( 'Legacy Templates', 'gravity-pdf' ),
+			'legacy_endpoint'    => __( 'Legacy PDF URLs', 'gravity-pdf' ),
+			'deprecated_filters' => __( 'Deprecated Filters', 'gravity-pdf' ),
+		];
+	}
+
+	/**
+	 * Fire one of the deprecated v3 filters, warning any third party still listening to it
+	 *
+	 * The notice is only emitted when a listener is actually attached, so sites that have already moved on stay
+	 * quiet.
+	 *
+	 * @param string $hook_name   The deprecated filter to fire
+	 * @param array  $args        The arguments to pass to the filter, the first of which is returned
+	 * @param string $replacement Override the mapped replacement, for dynamic hooks
+	 *
+	 * @return mixed
+	 * @since 6.17.0
+	 */
+	public static function apply_filters( string $hook_name, array $args, string $replacement = '' ) {
+		/* Sidestep building the deprecation message on the vast majority of sites, which have no listener */
+		if ( ! has_filter( $hook_name ) ) {
+			return $args[0];
+		}
+
+		if ( $replacement === '' ) {
+			$replacement = static::get_deprecated_filters()[ $hook_name ] ?? '';
+		}
+
+		static::log_deprecated_filter( $hook_name, $replacement );
+
+		return apply_filters_deprecated(
+			$hook_name,
+			$args,
+			'4.0',
+			$replacement,
+			sprintf(
+				/* translators: %s: The Gravity PDF version the filter is removed in */
+				esc_html__( 'This filter is removed in Gravity PDF %s.', 'gravity-pdf' ),
+				static::REMOVED_IN
+			)
+		);
+	}
+
+	/**
+	 * Record a deprecated filter with a third-party listener in the Gravity PDF log
+	 *
+	 * Written once per hook per request so a PDF that fires the same filter for every field doesn't flood the log.
+	 *
+	 * @param string $hook_name   The deprecated filter being fired
+	 * @param string $replacement The filter to use instead, if one exists
+	 *
+	 * @since 6.17.0
+	 */
+	protected static function log_deprecated_filter( string $hook_name, string $replacement ): void {
+		static $logged = [];
+
+		/* `gfpdfe_template_location` fires while the container is still being built, so the logger may not exist yet */
+		$log = \GPDFAPI::get_log_class();
+		if ( $log === null || isset( $logged[ $hook_name ] ) ) {
+			return;
+		}
+
+		$logged[ $hook_name ] = true;
+
+		$log->warning(
+			sprintf(
+				'The %1$s filter has a third-party listener attached and is removed in Gravity PDF %2$s.%3$s',
+				$hook_name,
+				static::REMOVED_IN,
+				$replacement !== '' ? sprintf( ' Use the %s filter instead.', $replacement ) : ''
+			)
+		);
+	}
+
+	/**
+	 * Record a hit on the legacy `?gf_pdf=` PDF endpoint
+	 *
+	 * Writes are throttled to one an hour, unless the request is for a form we haven't seen before.
+	 *
+	 * @param int $form_id The form the legacy URL requested a PDF for
+	 *
+	 * @since 6.17.0
+	 */
+	public static function record_legacy_endpoint_usage( int $form_id ): void {
+		$usage    = static::get_legacy_endpoint_usage();
+		$form_ids = $usage['form_ids'] ?? [];
+
+		$is_new    = ! in_array( $form_id, $form_ids, true ) && count( $form_ids ) < static::MAX_RECORDED_FORMS;
+		$throttled = ( time() - (int) ( $usage['last_used'] ?? 0 ) ) < HOUR_IN_SECONDS;
+
+		if ( ! $is_new && $throttled ) {
+			return;
+		}
+
+		if ( $is_new ) {
+			$form_ids[] = $form_id;
+			sort( $form_ids );
+		}
+
+		update_option(
+			static::ENDPOINT_USAGE_OPTION,
+			[
+				'last_used' => time(),
+				'form_ids'  => $form_ids,
+			],
+			false
+		);
+	}
+
+	/**
+	 * Get the recorded legacy `?gf_pdf=` PDF endpoint usage
+	 *
+	 * @return array Empty when the endpoint has never been hit
+	 * @since 6.17.0
+	 */
+	public static function get_legacy_endpoint_usage(): array {
+		$usage = get_option( static::ENDPOINT_USAGE_OPTION, [] );
+
+		return is_array( $usage ) ? $usage : [];
+	}
+
+	/**
+	 * Check if the v3 "Advanced Templating" (Tier 2) add-on is installed
+	 *
+	 * @since 6.17.0
+	 */
+	public static function has_tier_2_addon(): bool {
+		return class_exists( 'gfpdfe_business_plus' );
+	}
+
+	/**
+	 * Check if a PDF is configured to use the v3 Advanced Templating mode
+	 *
+	 * Compared case-insensitively, which is how the render path has always read the setting.
+	 *
+	 * @param array $settings The PDF settings
+	 *
+	 * @since 6.17.0
+	 */
+	public static function is_advanced_template_pdf( array $settings ): bool {
+		return strtolower( (string) ( $settings['advanced_template'] ?? '' ) ) === 'yes';
+	}
+
+	/**
+	 * Get the templates any PDF still renders through the v3 Advanced Templating mode
+	 *
+	 * Advanced Templating hands the template full control of the PDF, which only a v3-era template does, so the
+	 * setting identifies a legacy template even when the file itself carries a `Group` header.
+	 *
+	 * @return array List of absolute template paths
+	 * @since 6.17.0
+	 */
+	public static function get_advanced_template_paths(): array {
+		global $wpdb;
+
+		/* Narrow to the forms that mention the setting at all, so sites with a lot of forms don't load every one.
+		   Trashed forms are skipped: the user can't see them in their form list, so there's nothing to act on */
+		$meta_table = \GFFormsModel::get_meta_table_name();
+		$form_table = \GFFormsModel::get_form_table_name();
+
+		//phpcs:disable WordPress.DB.PreparedSQL.InterpolatedNotPrepared -- the table names come from Gravity Forms
+		$form_ids = $wpdb->get_col( //phpcs:ignore WordPress.DB.DirectDatabaseQuery.DirectQuery, WordPress.DB.DirectDatabaseQuery.NoCaching
+			$wpdb->prepare(
+				"SELECT meta.form_id FROM {$meta_table} meta
+				INNER JOIN {$form_table} form ON form.id = meta.form_id
+				WHERE form.is_trash = 0 AND meta.display_meta LIKE %s",
+				'%' . $wpdb->esc_like( 'advanced_template' ) . '%'
+			)
+		);
+		//phpcs:enable WordPress.DB.PreparedSQL.InterpolatedNotPrepared
+
+		$gform     = \GPDFAPI::get_form_class();
+		$templates = \GPDFAPI::get_templates_class();
+		$paths     = [];
+
+		foreach ( $form_ids as $form_id ) {
+			$form = $gform->get_form( (int) $form_id );
+
+			foreach ( $form['gfpdf_form_settings'] ?? [] as $pdf ) {
+				if ( ! static::is_advanced_template_pdf( $pdf ) ) {
+					continue;
+				}
+
+				try {
+					$paths[] = $templates->get_template_path_by_id( $pdf['template'] ?? '' );
+				} catch ( \Exception $e ) {
+					/* The PDF points at a template that no longer exists, so there's nothing to upgrade */
+					continue;
+				}
+			}
+		}
+
+		return $paths;
+	}
+
+	/**
+	 * Get any installed legacy (v3) PDF templates
+	 *
+	 * A template is classified as legacy when it has no `Group` header, which is how Helper_Templates groups
+	 * v3-era templates that predate the v4 header format, or when a PDF renders it through Advanced Templating.
+	 *
+	 * @return array List of absolute template paths
+	 * @since 6.17.0
+	 */
+	public static function get_legacy_templates(): array {
+		$templates = \GPDFAPI::get_templates_class();
+
+		$legacy = [];
+		foreach ( $templates->get_all_template_info() as $template ) {
+			if ( $templates->is_legacy_template( $template ) ) {
+				$legacy[] = $template['path'];
+			}
+		}
+
+		return array_values( array_unique( array_merge( $legacy, static::get_advanced_template_paths() ) ) );
+	}
+
+	/**
+	 * Get the deprecated v3 filters that currently have a third-party listener attached
+	 *
+	 * @param bool $scan_all Walk every registered hook, so dynamic filters like `gfpdfe_pdf_template_{form_id}` are
+	 *                       included. Off by default because `$wp_filter` holds thousands of entries on a real site,
+	 *                       and only the System Report displays the result.
+	 *
+	 * @return array<string, int> Hook name mapped to the number of listeners
+	 * @since 6.17.0
+	 */
+	public static function get_active_deprecated_filters( bool $scan_all = false ): array {
+		global $wp_filter;
+
+		$known = static::get_deprecated_filters();
+		$hooks = (array) $wp_filter;
+
+		/* Look the known hooks up by name, rather than filtering `$wp_filter`, which would walk all of it */
+		if ( ! $scan_all ) {
+			$hooks = [];
+
+			foreach ( array_keys( $known ) as $name ) {
+				if ( isset( $wp_filter[ $name ] ) ) {
+					$hooks[ $name ] = $wp_filter[ $name ];
+				}
+			}
+		}
+
+		$active = [];
+		foreach ( $hooks as $name => $hook ) {
+			if ( strpos( (string) $name, 'gfpdfe_' ) !== 0 && ! isset( $known[ $name ] ) ) {
+				continue;
+			}
+
+			$count = static::count_third_party_callbacks( $hook );
+			if ( $count > 0 ) {
+				$active[ $name ] = $count;
+			}
+		}
+
+		ksort( $active );
+
+		return $active;
+	}
+
+	/**
+	 * Count the callbacks on a hook, ignoring the one Gravity PDF registers itself
+	 *
+	 * @param \WP_Hook $hook
+	 *
+	 * @since 6.17.0
+	 */
+	protected static function count_third_party_callbacks( $hook ): int {
+		$count = 0;
+
+		foreach ( $hook->callbacks ?? [] as $callbacks ) {
+			foreach ( $callbacks as $callback ) {
+				if ( ( $callback['function'] ?? null ) === static::INTERNAL_FILTER_CALLBACK ) {
+					continue;
+				}
+
+				++$count;
+			}
+		}
+
+		return $count;
+	}
+
+	/**
+	 * Get every signal that the v3 backwards compatibility layer is in use on this site
+	 *
+	 * Signals with nothing to report are omitted, so the return value doubles as the list of features in use. The
+	 * template scan is cached for a day; the System Report always refreshes it, and takes the deeper filter scan
+	 * with it.
+	 *
+	 * @param bool $refresh Bypass the cache and re-run the scans
+	 *
+	 * @since 6.17.0
+	 */
+	public static function get_signals( bool $refresh = false ): array {
+		$legacy_templates = $refresh ? false : get_transient( static::SIGNAL_CACHE_KEY );
+
+		if ( ! is_array( $legacy_templates ) ) {
+			$legacy_templates = static::get_legacy_templates();
+
+			set_transient( static::SIGNAL_CACHE_KEY, $legacy_templates, DAY_IN_SECONDS );
+		}
+
+		return array_filter(
+			[
+				'legacy_templates'   => $legacy_templates,
+				'legacy_endpoint'    => static::get_legacy_endpoint_usage(),
+				'deprecated_filters' => static::get_active_deprecated_filters( $refresh ),
+			]
+		);
+	}
+}
diff --git a/src/Statics/Queue_Callbacks.php b/src/Statics/Queue_Callbacks.php
index e80c67d96..8bedec8b8 100644
--- a/src/Statics/Queue_Callbacks.php
+++ b/src/Statics/Queue_Callbacks.php
@@ -127,7 +127,7 @@ public static function send_notification( $form_id, $entry_id, $notification, $u
 	 * @deprecated 6.12 Caching layer + auto-purge added
 	 */
 	public static function cleanup_pdfs( $form_id, $entry_id ) {
-		_doing_it_wrong( __METHOD__, 'This method is deprecated and no alternative is available. The temporary cache is automatically cleaned every hour using the WP Cron.', '6.12' );
+		_deprecated_function( __METHOD__, '6.12' );
 
 		$gform = GPDFAPI::get_form_class();
 		$log   = GPDFAPI::get_log_class();
diff --git a/src/View/View_PDF.php b/src/View/View_PDF.php
index e4eb90818..343f29435 100644
--- a/src/View/View_PDF.php
+++ b/src/View/View_PDF.php
@@ -20,6 +20,7 @@
 use GFPDF\Helper\Helper_PDF;
 use GFPDF\Helper\Helper_Templates;
 use GFPDF\Statics\Debug;
+use GFPDF\Statics\Deprecation;
 use GFPDF\Statics\Kses;
 use GFPDFEntryDetail;
 use GFPDF_Vendor\Psr\Log\LoggerInterface;
@@ -151,7 +152,7 @@ public function __construct( array $data_cache, Helper_Abstract_Form $gform, Log
 	 * @deprecated 6.12.0 Use \GPDFAPI::create_pdf() to generate PDFs
 	 */
 	public function generate_pdf( $entry, $settings ) {
-		_doing_it_wrong( __METHOD__, 'Use \GPDFAPI::create_pdf() to generate PDFs', '6.12' );
+		_deprecated_function( __METHOD__, '6.12', '\GPDFAPI::create_pdf()' );
 
 		$controller = $this->getController();
 		$model      = $controller->model;
@@ -159,7 +160,7 @@ public function generate_pdf( $entry, $settings ) {
 
 		do_action( 'gfpdf_view_or_download_pdf', $form, $entry, $settings );
 
-		$settings['pdf_action'] = apply_filters( 'gfpdfe_pdf_output_type', $settings['pdf_action'] ?? 'download' ); /* Backwards compat */
+		$settings['pdf_action'] = Deprecation::apply_filters( 'gfpdfe_pdf_output_type', [ $settings['pdf_action'] ?? 'download' ] );
 
 		/* Setup the PDF that will be generated */
 		$pdf_generator = new Helper_PDF( $entry, $settings, $this->gform, $this->data, $this->misc, $this->templates, $this->log );
@@ -256,7 +257,7 @@ public function generate_pdf( $entry, $settings ) {
 	 * @deprecated 4.1
 	 */
 	public function get_template_filename( $name ) {
-		_doing_it_wrong( __METHOD__, 'This method has been replaced by Helper_Misc::get_file_with_extension().', '4.1' );
+		_deprecated_function( __METHOD__, '4.1', 'Helper_Misc::get_file_with_extension()' );
 
 		return $this->misc->get_file_with_extension( $name, '.php' );
 	}
@@ -496,6 +497,7 @@ public function show_form_title( $show_title, $form ) {
 	 * @deprecated 6.10.1 Page fields are handled like all other fields, with markup generated using a dedicated Field_Page class
 	 */
 	public function display_page_name( $page, $form, Helper_Field_Container $container ) {
+		_deprecated_function( __METHOD__, '6.10.1', 'GFPDF\Helper\Fields\Field_Page' );
 
 		/* Only display the current page name if it exists */
 		if ( isset( $form['pagination']['pages'][ $page ] ) && strlen( trim( $form['pagination']['pages'][ $page ] ) ) > 0 ) {
@@ -540,13 +542,24 @@ public function display_page_name( $page, $form, Helper_Field_Container $contain
 	 * @since 4.0
 	 */
 	public function autoprocess_core_template_options( $html, $form, $entry, $settings ) {
-		/* Prevent core styles loading if a v3 template or using our legacy Tier 2 add-on */
 		$template_info = $this->templates->get_template_info_by_id( $settings['template'] );
-		if (
-			( esc_html__( 'Legacy', 'gravity-pdf' ) !== $template_info['group'] ) &&
-			( empty( $settings['advanced_template'] ) || 'Yes' !== $settings['advanced_template'] )
-		) {
-			$html = $this->get_core_template_styles( $settings, $entry ) . $html;
+		$is_legacy     = $this->templates->is_legacy_template( $template_info );
+		$is_tier_2     = Deprecation::is_advanced_template_pdf( $settings );
+
+		/* Prevent core styles loading if a v3 template or using our legacy Tier 2 add-on */
+		if ( ! $is_legacy && ! $is_tier_2 ) {
+			return $this->get_core_template_styles( $settings, $entry ) . $html;
+		}
+
+		/* Model_PDF::handle_legacy_tier_2_processing() warns about the Advanced Templating half of this */
+		if ( $is_legacy ) {
+			$this->log->warning(
+				sprintf( 'This PDF uses a legacy (v3) template, which is removed in Gravity PDF %s. See https://docs.gravitypdf.com/developers/upgrade-legacy-template/ for upgrade instructions.', Deprecation::REMOVED_IN ),
+				[
+					'template' => $settings['template'],
+					'pdf_id'   => $settings['id'] ?? '',
+				]
+			);
 		}
 
 		return $html;
diff --git a/src/View/View_Settings.php b/src/View/View_Settings.php
index a0b121a01..47d09a826 100644
--- a/src/View/View_Settings.php
+++ b/src/View/View_Settings.php
@@ -137,6 +137,8 @@ public function __construct( array $data_cache, Helper_Abstract_Form $gform, Log
 	 * @deprecated 6.4
 	 */
 	public function tabs() {
+		_deprecated_function( __METHOD__, '6.4', 'View_Settings::sub_menu()' );
+
 		ob_start();
 		$this->sub_menu();
 
diff --git a/src/View/View_System_Report.php b/src/View/View_System_Report.php
index 03aeeb722..aed0b80d4 100644
--- a/src/View/View_System_Report.php
+++ b/src/View/View_System_Report.php
@@ -5,6 +5,7 @@
 namespace GFPDF\View;
 
 use GFPDF\Helper\Helper_Abstract_View;
+use GFPDF\Statics\Deprecation;
 
 /**
  * @package     Gravity PDF
@@ -146,6 +147,230 @@ public function get_template_check_message( string $path, string $template_versi
 	public function get_template_upgrade_message(): string {
 		$learn_more_url = 'https://docs.gravitypdf.com/developers/template-hierarchy';
 
-		return $this->markup_warning . ' <a href="' . $learn_more_url . '">' . esc_html__( 'Learn how to update', 'gravity-pdf' ) . '</a>';
+		return $this->markup_warning . ' <a href="' . esc_url( $learn_more_url ) . '">' . esc_html__( 'Learn how to update', 'gravity-pdf' ) . '</a>';
+	}
+
+	/**
+	 * Describe one of the deprecated features detected on this site
+	 *
+	 * Shared by the Gravity Forms system report and the Site Health test, which present the same detections
+	 * differently.
+	 *
+	 * @param string $key    The signal key from Deprecation::get_signals()
+	 * @param array  $signal The detections recorded for that signal
+	 *
+	 * @return array One `lines` entry per detection, plus the `advice` to act on and the `url` explaining it. The
+	 *               text is unescaped, as one of the three consumers is the Site Health Info tab, which escapes
+	 *               what it's given.
+	 * @since 6.17.0
+	 */
+	public function get_deprecated_feature( string $key, array $signal ): array {
+		$methods = [
+			'legacy_templates'   => 'get_legacy_templates_feature',
+			'legacy_endpoint'    => 'get_legacy_endpoint_feature',
+			'deprecated_filters' => 'get_deprecated_filter_feature',
+		];
+
+		return $this->{$methods[ $key ]}( $signal );
+	}
+
+	/**
+	 * Describe any installed legacy (v3) template file(s)
+	 *
+	 * @param array $paths The paths to the legacy PDF template files
+	 *
+	 * @since 6.17.0
+	 */
+	protected function get_legacy_templates_feature( array $paths ): array {
+		$lines = [];
+
+		foreach ( $paths as $path ) {
+			/* translators: %s: Template file path */
+			$lines[] = sprintf( __( '%s is a legacy template and is no longer supported', 'gravity-pdf' ), $path );
+		}
+
+		return [
+			'lines'  => $lines,
+			'advice' => __( 'Learn how to upgrade legacy templates', 'gravity-pdf' ),
+			'url'    => 'https://docs.gravitypdf.com/developers/upgrade-legacy-template/',
+		];
+	}
+
+	/**
+	 * Describe recorded use of the legacy `?gf_pdf=` PDF endpoint
+	 *
+	 * @param array $usage The recorded usage, containing `last_used` and `form_ids` keys
+	 *
+	 * @since 6.17.0
+	 */
+	protected function get_legacy_endpoint_feature( array $usage ): array {
+		$last_used = wp_date( get_option( 'date_format' ), (int) $usage['last_used'] );
+		$form_ids  = implode( ', ', array_map( 'intval', $usage['form_ids'] ) );
+
+		return [
+			/* translators: 1: Date the legacy URL was last requested, 2: Comma separated list of form IDs */
+			'lines'  => [ sprintf( __( 'Legacy PDF URLs were last requested on %1$s for form(s) %2$s', 'gravity-pdf' ), $last_used, $form_ids ) ],
+			'advice' => __( 'Replace these links with the [gravitypdf] shortcode or PDF merge tags', 'gravity-pdf' ),
+			'url'    => 'https://docs.gravitypdf.com/v6/users/shortcodes-and-mergetags',
+		];
+	}
+
+	/**
+	 * Describe the deprecated v3 filters that have a third-party listener attached
+	 *
+	 * @param array $filters Hook name mapped to the number of listeners
+	 *
+	 * @since 6.17.0
+	 */
+	protected function get_deprecated_filter_feature( array $filters ): array {
+		$lines = [];
+
+		foreach ( $filters as $name => $count ) {
+			/* translators: 1: Filter name, 2: Number of callbacks attached to it */
+			$lines[] = sprintf( __( '%1$s has %2$d listener(s)', 'gravity-pdf' ), $name, $count );
+		}
+
+		return [
+			'lines'  => $lines,
+			'advice' => __( 'Move these listeners to their Gravity PDF 6 equivalent', 'gravity-pdf' ),
+			'url'    => 'https://docs.gravitypdf.com/developers/filters/',
+		];
+	}
+
+	/**
+	 * Assemble the display and export values for a Deprecated Features row
+	 *
+	 * @param string $key    The signal key from Deprecation::get_signals()
+	 * @param array  $signal The detections recorded for that signal
+	 *
+	 * @since 6.17.0
+	 */
+	public function get_deprecated_feature_message( string $key, array $signal ): array {
+		$feature      = $this->get_deprecated_feature( $key, $signal );
+		$value        = '';
+		$value_export = '';
+
+		foreach ( $feature['lines'] as $line ) {
+			$value        .= esc_html( $line ) . $this->get_icon( false ) . '<hr>';
+			$value_export .= $line . "   &#10008;\n";
+		}
+
+		return [
+			'value'        => $value . $this->get_removal_message( $feature['advice'], $feature['url'] ),
+			'value_export' => $value_export,
+		];
+	}
+
+	/**
+	 * Build the Site Health test result for the deprecated features detected on this site
+	 *
+	 * Unlike the one-time admin notice, this surface can't be dismissed: it clears itself once the site stops
+	 * using the v3 layer, and returns if it starts again.
+	 *
+	 * @param array $signals The signals from Deprecation::get_signals()
+	 *
+	 * @since 6.17.0
+	 */
+	public function get_deprecated_features_test( array $signals ): array {
+		$result = [
+			'label'       => esc_html__( 'Your site does not use deprecated Gravity PDF functionality', 'gravity-pdf' ),
+			'status'      => 'good',
+			'badge'       => [
+				'label' => esc_html__( 'Gravity PDF', 'gravity-pdf' ),
+				'color' => 'blue',
+			],
+			'description' => '<p>' . sprintf(
+				/* translators: %s: The Gravity PDF version the functionality is removed in */
+				esc_html__( 'Gravity PDF %s removes functionality carried over from version 3. Nothing on this site relies on it.', 'gravity-pdf' ),
+				esc_html( Deprecation::REMOVED_IN )
+			) . '</p>',
+			'actions'     => '',
+			'test'        => 'gravity_pdf_deprecated_features',
+		];
+
+		if ( $signals === [] ) {
+			return $result;
+		}
+
+		$labels = Deprecation::get_feature_labels();
+
+		$result['status'] = 'recommended';
+		$result['label']  = sprintf(
+			/* translators: %s: The Gravity PDF version the functionality is removed in */
+			esc_html__( 'Your site uses Gravity PDF functionality that is removed in version %s', 'gravity-pdf' ),
+			esc_html( Deprecation::REMOVED_IN )
+		);
+
+		$result['description'] = '<p>' . sprintf(
+			/* translators: %s: The Gravity PDF version the functionality is removed in */
+			esc_html__( 'The following functionality dates back to Gravity PDF version 3 and is removed in version %s. Update it before then, or the PDFs that rely on it will stop working.', 'gravity-pdf' ),
+			esc_html( Deprecation::REMOVED_IN )
+		) . '</p>';
+
+		foreach ( $signals as $key => $signal ) {
+			$feature = $this->get_deprecated_feature( $key, $signal );
+
+			$result['description'] .= '<p><strong>' . esc_html( $labels[ $key ] ) . '</strong></p>';
+			$result['description'] .= '<ul><li>' . implode( '</li><li>', array_map( 'esc_html', $feature['lines'] ) ) . '</li></ul>';
+			$result['description'] .= '<p><a href="' . esc_url( $feature['url'] ) . '">' . esc_html( $feature['advice'] ) . '</a></p>';
+		}
+
+		$result['actions'] = '<p><a href="' . esc_url( admin_url( 'admin.php?page=gf_system_status' ) ) . '">' . esc_html__( 'View the Gravity Forms system report', 'gravity-pdf' ) . '</a></p>';
+
+		return $result;
+	}
+
+	/**
+	 * Prepare the trailing advice shown under each deprecated feature
+	 *
+	 * @param string $advice The action the user should take
+	 * @param string $url    Where to read more about that action
+	 *
+	 * @since 6.17.0
+	 */
+	protected function get_removal_message( string $advice, string $url ): string {
+		/* translators: %s: The Gravity PDF version the feature is removed in */
+		$removal = sprintf( esc_html__( 'Removed in Gravity PDF %s.', 'gravity-pdf' ), Deprecation::REMOVED_IN );
+
+		return $this->markup_warning . ' ' . $removal . ' <a href="' . esc_url( $url ) . '">' . esc_html( $advice ) . '</a>';
+	}
+
+	/**
+	 * Build the Site Health Info tab section for the deprecated features detected on this site
+	 *
+	 * This is the tab users copy into a support ticket, so the section is always present: when nothing is
+	 * detected it says so, rather than leaving the reader to guess whether the check ran.
+	 *
+	 * @param array $signals The signals from Deprecation::get_signals()
+	 *
+	 * @since 6.17.0
+	 */
+	public function get_deprecated_debug_information( array $signals ): array {
+		$labels = Deprecation::get_feature_labels();
+		$fields = [];
+
+		foreach ( $signals as $key => $signal ) {
+			$fields[ $key ] = [
+				'label' => $labels[ $key ],
+				'value' => implode( '; ', $this->get_deprecated_feature( $key, $signal )['lines'] ),
+			];
+		}
+
+		if ( $fields === [] ) {
+			$fields['deprecated_features'] = [
+				'label' => __( 'Deprecated functionality', 'gravity-pdf' ),
+				'value' => __( 'None detected', 'gravity-pdf' ),
+			];
+		}
+
+		return [
+			'label'       => __( 'Gravity PDF - Deprecated Functionality', 'gravity-pdf' ),
+			'description' => sprintf(
+				/* translators: %s: The Gravity PDF version the functionality is removed in */
+				esc_html__( 'Functionality carried over from Gravity PDF version 3, which is removed in version %s.', 'gravity-pdf' ),
+				esc_html( Deprecation::REMOVED_IN )
+			),
+			'fields'      => $fields,
+		];
 	}
 }
diff --git a/src/bootstrap.php b/src/bootstrap.php
index 9f5a75c6e..c0a694a07 100644
--- a/src/bootstrap.php
+++ b/src/bootstrap.php
@@ -130,8 +130,7 @@ class Router implements Helper\Helper_Interface_Actions, Helper\Helper_Interface
 	 * @since 4.0
 	 */
 	public function __call( $name, $arguments ) {
-		/* translators: %s: deprecated method name */
-		_doing_it_wrong( esc_html( $name ), esc_html( sprintf( __( '"%s" has been deprecated as of Gravity PDF 4.0', 'gravity-pdf' ), $name ) ), '4.0' );
+		_deprecated_function( esc_html( $name ), '4.0' );
 	}
 
 	/**
@@ -143,7 +142,7 @@ public function __call( $name, $arguments ) {
 	 * @since  4.0
 	 */
 	public static function __callStatic( $name, $arguments ) {
-		_doing_it_wrong( esc_html( $name ), esc_html( sprintf( __( '"%s" has been deprecated as of Gravity PDF 4.0', 'gravity-pdf' ), $name ) ), '4.0' );
+		_deprecated_function( esc_html( $name ), '4.0' );
 	}
 
 	/**
@@ -920,7 +919,7 @@ public function load_debug() {
 	public function check_system_status() {
 		$view  = new View\View_System_Report();
 		$model = new Model\Model_System_Report( $this->options, $this->data, $this->log, $this->misc, new GFPDF_Major_Compatibility_Checks(), $this->templates );
-		$class = new Controller\Controller_System_Report( $model, $view );
+		$class = new Controller\Controller_System_Report( $model, $view, $this->gform );
 		$class->init();
 
 		$this->singleton->add_class( $class );
diff --git a/src/deprecated.php b/src/deprecated.php
index 202c6817f..fca9b949b 100644
--- a/src/deprecated.php
+++ b/src/deprecated.php
@@ -42,7 +42,7 @@ abstract class GFPDF_Deprecated_Abstract {
 	 *
 	 */
 	public function __call( $name, $arguments ) {
-		_doing_it_wrong( esc_html( $name ), esc_html( sprintf( __( '"%s" has been deprecated as of Gravity PDF 4.0', 'gravity-pdf' ), $name ) ), '4.0' );
+		_deprecated_function( esc_html( static::class . '::' . $name ), '4.0' );
 	}
 
 	/**
@@ -55,7 +55,7 @@ public function __call( $name, $arguments ) {
 	 *
 	 */
 	public static function __callStatic( $name, $arguments ) {
-		_doing_it_wrong( esc_html( $name ), esc_html( sprintf( __( '"%s" has been deprecated as of Gravity PDF 4.0', 'gravity-pdf' ), $name ) ), '4.0' );
+		_deprecated_function( esc_html( static::class . '::' . $name ), '4.0' );
 	}
 }
 
@@ -130,6 +130,7 @@ class PDFRender extends GFPDF_Deprecated_Abstract {
 	 * @since 3.0
 	 */
 	public function savePDF( $raw_pdf_string, $filename, $id ) {
+		_deprecated_function( __METHOD__, '4.0', 'GPDFAPI::create_pdf()' );
 
 		/* create our path */
 		$path = apply_filters( 'gfpdf_legacy_save_path', PDF_SAVE_LOCATION . $id . '/', $filename, $id );
@@ -166,6 +167,7 @@ public function savePDF( $raw_pdf_string, $filename, $id ) {
 	 *
 	 */
 	public static function prepare_ids( $form_id, $lead_id, $template, $id, $output, $filename, $arguments, $args ) {
+		/* No deprecation notice — core registers this callback itself on `gfpdfe_pre_load_template` */
 		global $lead_ids;
 		$lead_ids = $args['lead_ids'];
 
@@ -188,6 +190,8 @@ class PDF_Common extends GFPDF_Deprecated_Abstract {
 	 * @since 4.0
 	 */
 	public static function get_ids() {
+		_deprecated_function( __METHOD__, '4.0' );
+
 		global $form_id, $lead_id, $lead_ids;
 
 		$form_id  = ! empty( (int) $form_id ) ? (int) $form_id : (int) rgget( 'fid' );
@@ -209,6 +213,8 @@ public static function get_ids() {
 	 * @since 3.0
 	 */
 	public static function get_upload_dir() {
+		_deprecated_function( __METHOD__, '4.0', 'Helper_Misc::get_upload_details()' );
+
 		$misc = GPDFAPI::get_misc_class();
 
 		return $misc->get_upload_details();
@@ -226,6 +232,8 @@ public static function get_upload_dir() {
 	 * @since 3.0
 	 */
 	public static function do_mergetags( $text, $form_id, $lead_id ) {
+		_deprecated_function( __METHOD__, '4.0', 'Helper_Form::process_tags()' );
+
 		$gform = GPDFAPI::get_form_class();
 
 		return $gform->process_tags( $text, $gform->get_form( $form_id ), $gform->get_entry( $lead_id ) );
@@ -239,6 +247,8 @@ public static function do_mergetags( $text, $form_id, $lead_id ) {
 	 * @since 4.0
 	 */
 	public static function view_data( $form_data ) {
+		_deprecated_function( __METHOD__, '4.0' );
+
 		$pdf_view = \GPDFAPI::get_pdf_class();
 		$pdf_view->maybe_view_form_data( $form_data );
 	}
@@ -253,6 +263,8 @@ public static function view_data( $form_data ) {
 	 * @since 3.0
 	 */
 	public static function post( $name ) {
+		_deprecated_function( __METHOD__, '4.0' );
+
 		/* phpcs:ignore WordPress.Security.NonceVerification.Missing */
 		if ( isset( $_POST[ $name ] ) ) {
 			/* phpcs:ignore WordPress.Security.NonceVerification.Missing */
@@ -272,6 +284,8 @@ public static function post( $name ) {
 	 * @since 3.0
 	 */
 	public static function get( $name ) {
+		_deprecated_function( __METHOD__, '4.0' );
+
 		/* phpcs:ignore WordPress.Security.NonceVerification.Recommended */
 		if ( isset( $_GET[ $name ] ) ) {
 			/* phpcs:ignore WordPress.Security.NonceVerification.Recommended */
@@ -292,6 +306,8 @@ public static function get( $name ) {
 	 * @since 3.0
 	 */
 	public static function get_pdf_filename( $form_id, $lead_id ) {
+		_deprecated_function( __METHOD__, '4.0', 'GPDFAPI::get_pdf_filename()' );
+
 		return "form-$form_id-entry-$lead_id.pdf";
 	}
 
@@ -305,6 +321,8 @@ public static function get_pdf_filename( $form_id, $lead_id ) {
 	 * @since 4.0
 	 */
 	public static function remove_invalid_characters( $name ) {
+		_deprecated_function( __METHOD__, '4.0', 'Helper_Misc::strip_invalid_characters()' );
+
 		$misc = GPDFAPI::get_misc_class();
 
 		return $misc->strip_invalid_characters( $name );
@@ -316,6 +334,7 @@ public static function remove_invalid_characters( $name ) {
 	 * @since 3.0
 	 */
 	public static function setup_ids() {
+		_deprecated_function( __METHOD__, '4.0' );
 	}
 }
 
@@ -342,6 +361,8 @@ class GFPDFEntryDetail extends GFPDF_Deprecated_Abstract {
 	 * @since 3.0
 	 */
 	public static function lead_detail_grid( $form, $lead, $allow_display_empty_fields = false, $show_html = false, $show_page_name = false, $should_return = false ) {
+		_deprecated_function( __METHOD__, '4.0' );
+
 		$config = [
 			'meta' => [
 				'empty_field' => $allow_display_empty_fields,
@@ -367,6 +388,7 @@ public static function lead_detail_grid( $form, $lead, $allow_display_empty_fiel
 	 * @since 3.7
 	 */
 	public static function do_lead_detail_grid( $form, $lead, $config = [] ) {
+		_deprecated_function( __METHOD__, '4.0' );
 
 		/* Convert old config values to our new ones */
 		if ( ! isset( $config['meta'] ) ) {
@@ -614,6 +636,8 @@ public static function load_legacy_css( GF_Field $field ) {
 	 * @since 3.0
 	 */
 	public static function lead_detail_grid_array( $form, $lead ) {
+		_deprecated_function( __METHOD__, '4.0', 'GPDFAPI::get_form_data()' );
+
 		$model = GPDFAPI::get_pdf_class( 'model' );
 
 		return $model->get_form_data( $lead );
@@ -630,6 +654,8 @@ public static function lead_detail_grid_array( $form, $lead ) {
 	 * @since 3.0
 	 */
 	public static function product_table( $form, $lead ) {
+		_deprecated_function( __METHOD__, '4.0', 'GPDFAPI::product_table()' );
+
 		GPDFAPI::product_table( $lead );
 	}
 
@@ -645,6 +671,8 @@ public static function product_table( $form, $lead ) {
 	 * @since 3.0
 	 */
 	public static function get_likert( $form, $lead, $field_id ) {
+		_deprecated_function( __METHOD__, '4.0', 'GPDFAPI::likert_table()' );
+
 		return GPDFAPI::likert_table( $lead, $field_id, true );
 	}
 }
@@ -680,6 +708,8 @@ class GFPDF_Core_Model extends GFPDF_Deprecated_Abstract {
 	 * @since 3.0
 	 */
 	public static function gfpdfe_save_pdf( $entry, $form ) {
+		_deprecated_function( __METHOD__, '4.0', 'GPDFAPI::create_pdf()' );
+
 		$pdfs = GPDFAPI::get_entry_pdfs( $entry['id'] );
 
 		if ( ! is_wp_error( $pdfs ) ) {
@@ -734,6 +764,7 @@ class mPDF {
 		 * @since 5.0
 		 */
 		public function __construct( $mode = '', $format = 'A4', $default_font_size = 0, $default_font = '', $mgl = 15, $mgr = 15, $mgt = 16, $mgb = 16, $mgh = 9, $mgf = 9, $orientation = 'P' ) {
+			_deprecated_function( 'mPDF::__construct', '5.0', 'GFPDF\Helper\Mpdf\Mpdf' );
 
 			$data                = GPDFAPI::get_data_class();
 			$default_font_config = ( new FontVariables() )->getDefaults();
diff --git a/tests/phpunit/integration/Controller/Test_Controller_Actions.php b/tests/phpunit/integration/Controller/Test_Controller_Actions.php
index beb4cddcb..a9e20015c 100644
--- a/tests/phpunit/integration/Controller/Test_Controller_Actions.php
+++ b/tests/phpunit/integration/Controller/Test_Controller_Actions.php
@@ -42,10 +42,11 @@ public function test_init_registers_admin_init_hooks() {
 		$this->assertNotFalse( has_action( 'admin_init', [ $this->controller, 'route_notices' ] ) );
 	}
 
-	public function test_get_routes_includes_default_core_fonts_route() {
+	public function test_get_routes_includes_default_routes() {
 		$routes = $this->controller->get_routes();
 
 		$this->assertCount( 1, $routes );
+
 		$this->assertSame( 'install_core_fonts', $routes[0]['action'] );
 		$this->assertSame( 'gravityforms_edit_settings', $routes[0]['capability'] );
 		$this->assertIsCallable( $routes[0]['condition'] );
@@ -82,6 +83,49 @@ public function test_route_notices_short_circuits_on_getting_started_page() {
 		$this->assertFalse( $gfpdf->notices->has_notice() );
 	}
 
+	public function test_route_notices_skips_pages_the_notice_cannot_display_on() {
+		global $gfpdf, $pagenow;
+
+		wp_set_current_user( self::factory()->user->create( [ 'role' => 'administrator' ] ) );
+		set_current_screen( 'dashboard' );
+
+		add_filter(
+			'gfpdf_one_time_action_routes',
+			static function () {
+				return [
+					[
+						'action'      => 'always_notify',
+						'action_text' => 'Do it',
+						'condition'   => '__return_true',
+						'process'     => '__return_true',
+						'view'        => static function () {
+							return 'A notice';
+						},
+						'capability'  => 'gravityforms_view_settings',
+					],
+				];
+			}
+		);
+
+		$original = $pagenow;
+		$pagenow  = 'upload.php';
+
+		$gfpdf->notices->clear();
+		$this->controller->route_notices();
+
+		$this->assertFalse( $gfpdf->notices->has_notice() );
+
+		$pagenow = 'index.php';
+
+		$this->controller->route_notices();
+
+		$this->assertTrue( $gfpdf->notices->has_notice() );
+
+		$pagenow = $original;
+		remove_all_filters( 'gfpdf_one_time_action_routes' );
+		$gfpdf->notices->clear();
+	}
+
 	public function test_route_dismisses_notice_when_dismiss_flag_set() {
 		global $gfpdf;
 
diff --git a/tests/phpunit/integration/Controller/Test_Controller_Install.php b/tests/phpunit/integration/Controller/Test_Controller_Install.php
index ab801e558..ef50596f2 100644
--- a/tests/phpunit/integration/Controller/Test_Controller_Install.php
+++ b/tests/phpunit/integration/Controller/Test_Controller_Install.php
@@ -95,7 +95,7 @@ static function ( $old, $new ) use ( &$captured ) {
 	}
 
 	public function test_maybe_uninstall_emits_doing_it_wrong_notice() {
-		$this->setExpectedIncorrectUsage( 'GFPDF\Controller\Controller_Install::maybe_uninstall' );
+		$this->setExpectedDeprecated( 'GFPDF\Controller\Controller_Install::maybe_uninstall' );
 
 		$this->controller->maybe_uninstall();
 	}
diff --git a/tests/phpunit/integration/Controller/Test_Controller_PDF.php b/tests/phpunit/integration/Controller/Test_Controller_PDF.php
index 68f9f41ab..2e371fdc6 100644
--- a/tests/phpunit/integration/Controller/Test_Controller_PDF.php
+++ b/tests/phpunit/integration/Controller/Test_Controller_PDF.php
@@ -126,7 +126,7 @@ public function test_prevent_index_defines_donotcachepage_constant() {
 	}
 
 	public function test_sgoptimizer_html_minification_fix_emits_doing_it_wrong() {
-		$this->setExpectedIncorrectUsage( 'GFPDF\Controller\Controller_PDF::sgoptimizer_html_minification_fix' );
+		$this->setExpectedDeprecated( 'GFPDF\Controller\Controller_PDF::sgoptimizer_html_minification_fix' );
 
 		$this->controller->sgoptimizer_html_minification_fix();
 	}
@@ -173,8 +173,8 @@ public function test_add_current_form_object_hooks_returns_form_unchanged_when_i
 	 * @group slow
 	 */
 	public function test_process_legacy_pdf_endpoint() {
-		$this->setExpectedIncorrectUsage( 'GFPDF\Controller\Controller_PDF::process_legacy_pdf_endpoint' );
-		$this->setExpectedIncorrectUsage( 'GFPDF\Model\Model_PDF::get_legacy_config' );
+		$this->setExpectedDeprecated( 'GFPDF\Controller\Controller_PDF::process_legacy_pdf_endpoint' );
+		$this->setExpectedDeprecated( 'GFPDF\Model\Model_PDF::get_legacy_config' );
 
 		/* Test our endpoint is firing correctly */
 		$results = $this->form_and_entry();
diff --git a/tests/phpunit/integration/Controller/Test_Controller_Pdf_Queue.php b/tests/phpunit/integration/Controller/Test_Controller_Pdf_Queue.php
index e2ec21ce8..90b3eb1a6 100644
--- a/tests/phpunit/integration/Controller/Test_Controller_Pdf_Queue.php
+++ b/tests/phpunit/integration/Controller/Test_Controller_Pdf_Queue.php
@@ -363,8 +363,8 @@ public function test_queue_dispatch_resend_notification_tasks() {
 	 * @since 5.0
 	 */
 	public function test_cleanup_pdfs() {
-		$this->setExpectedIncorrectUsage( 'GFPDF\Statics\Queue_Callbacks::cleanup_pdfs' );
-		$this->setExpectedIncorrectUsage( 'GFPDF\Model\Model_PDF::cleanup_pdf' );
+		$this->setExpectedDeprecated( 'GFPDF\Statics\Queue_Callbacks::cleanup_pdfs' );
+		$this->setExpectedDeprecated( 'GFPDF\Model\Model_PDF::cleanup_pdf' );
 
 		$form_class = \GPDFAPI::get_form_class();
 
diff --git a/tests/phpunit/integration/Controller/Test_Controller_System_Report.php b/tests/phpunit/integration/Controller/Test_Controller_System_Report.php
index 2dbe45385..84d2a27f3 100644
--- a/tests/phpunit/integration/Controller/Test_Controller_System_Report.php
+++ b/tests/phpunit/integration/Controller/Test_Controller_System_Report.php
@@ -4,6 +4,7 @@
 
 namespace GFPDF\Controller;
 
+use GFPDF\Statics\Deprecation;
 use GFPDF\Tests\Integration\TestCase;
 
 /**
@@ -88,4 +89,152 @@ public function test_system_report_outdated_template() {
 
 		@unlink( $override_path );
 	}
+
+	/**
+	 * Get the items of the Deprecated Features section, which is only present when something is detected
+	 */
+	protected function get_deprecated_features(): array {
+		$system_report = apply_filters( 'gform_system_report', [] );
+
+		return $system_report[0]['tables'][4]['items'] ?? [];
+	}
+
+	public function test_system_report_has_no_deprecated_features_section_by_default() {
+		$system_report = apply_filters( 'gform_system_report', [] );
+
+		$this->assertCount( 4, $system_report[0]['tables'] );
+	}
+
+	public function test_system_report_legacy_template() {
+		$this->assertArrayNotHasKey( 'legacy_templates', $this->get_deprecated_features() );
+
+		/* install a v3 template (no headers), then verify it gets flagged as legacy */
+		$data        = \GPDFAPI::get_data_class();
+		$legacy_path = $data->template_location . 'my-legacy-template.php';
+
+		file_put_contents( $legacy_path, '<?php if ( ! class_exists( "RGForms" ) ) { return; } ?>' );
+
+		/* the template list is memoized per request by GFCache */
+		\GFCache::flush();
+
+		$items = $this->get_deprecated_features();
+		$this->assertArrayHasKey( 'legacy_templates', $items );
+		$this->assertStringContainsString( 'my-legacy-template.php', $items['legacy_templates']['value_export'] );
+
+		@unlink( $legacy_path );
+
+		/* drop the cached list again so later tests don't read the deleted file */
+		\GFCache::flush();
+	}
+
+	public function test_system_report_legacy_endpoint() {
+		$this->assertArrayNotHasKey( 'legacy_endpoint', $this->get_deprecated_features() );
+
+		Deprecation::record_legacy_endpoint_usage( 42 );
+
+		$items = $this->get_deprecated_features();
+		$this->assertArrayHasKey( 'legacy_endpoint', $items );
+		$this->assertStringContainsString( '42', $items['legacy_endpoint']['value_export'] );
+	}
+
+	public function test_system_report_advanced_templating_is_reported_as_a_legacy_template() {
+		$this->assertArrayNotHasKey( 'legacy_templates', $this->get_deprecated_features() );
+
+		$gform                       = \GPDFAPI::get_form_class();
+		$form                        = $gform->get_form( $this->gf_factory()->form->create() );
+		$form['gfpdf_form_settings'] = [
+			'abc123' => [
+				'id'                => 'abc123',
+				'name'              => 'My Tier 2 PDF',
+				'template'          => 'zadani',
+				'advanced_template' => 'Yes',
+			],
+		];
+
+		$gform->update_form( $form );
+
+		/* Advanced Templating has no row of its own: the template it renders is reported as a legacy one */
+		$items = $this->get_deprecated_features();
+		$this->assertArrayNotHasKey( 'advanced_templating', $items );
+		$this->assertStringContainsString( 'zadani.php', $items['legacy_templates']['value_export'] );
+	}
+
+	public function test_system_report_deprecated_filters() {
+		$this->assertArrayNotHasKey( 'deprecated_filters', $this->get_deprecated_features() );
+
+		$callback = static function ( $name ) {
+			return $name;
+		};
+
+		add_filter( 'gfpdfe_pdf_filename', $callback );
+
+		$items = $this->get_deprecated_features();
+		$this->assertArrayHasKey( 'deprecated_filters', $items );
+		$this->assertStringContainsString( 'gfpdfe_pdf_filename', $items['deprecated_filters']['value_export'] );
+
+		remove_filter( 'gfpdfe_pdf_filename', $callback );
+	}
+
+	/**
+	 * Get the Site Health test the controller registers
+	 */
+	protected function get_site_health_test(): array {
+		$tests = apply_filters( 'site_status_tests', [ 'direct' => [] ] );
+
+		return $tests['direct']['gravity_pdf_deprecated_features'] ?? [];
+	}
+
+	public function test_site_health_test_is_registered() {
+		wp_set_current_user( self::factory()->user->create( [ 'role' => 'administrator' ] ) );
+
+		$test = $this->get_site_health_test();
+
+		$this->assertIsCallable( $test['test'] );
+		$this->assertSame( 'good', call_user_func( $test['test'] )['status'] );
+	}
+
+	public function test_site_health_test_is_gated_on_the_gravity_forms_capability() {
+		wp_set_current_user( self::factory()->user->create( [ 'role' => 'subscriber' ] ) );
+
+		$this->assertSame( [], $this->get_site_health_test() );
+	}
+
+	public function test_debug_information_reports_a_clean_site() {
+		wp_set_current_user( self::factory()->user->create( [ 'role' => 'administrator' ] ) );
+
+		$info = apply_filters( 'debug_information', [] );
+
+		$this->assertSame( 'None detected', $info['gravity-pdf-deprecated']['fields']['deprecated_features']['value'] );
+	}
+
+	public function test_debug_information_is_gated_on_the_gravity_forms_capability() {
+		wp_set_current_user( self::factory()->user->create( [ 'role' => 'subscriber' ] ) );
+
+		$this->assertArrayNotHasKey( 'gravity-pdf-deprecated', apply_filters( 'debug_information', [] ) );
+	}
+
+	public function test_debug_information_reports_each_signal() {
+		wp_set_current_user( self::factory()->user->create( [ 'role' => 'administrator' ] ) );
+
+		Deprecation::record_legacy_endpoint_usage( 42 );
+
+		$fields = apply_filters( 'debug_information', [] )['gravity-pdf-deprecated']['fields'];
+
+		$this->assertArrayNotHasKey( 'deprecated_features', $fields );
+		$this->assertSame( 'Legacy PDF URLs', $fields['legacy_endpoint']['label'] );
+		$this->assertStringContainsString( '42', $fields['legacy_endpoint']['value'] );
+	}
+
+	public function test_site_health_test_reports_each_signal() {
+		wp_set_current_user( self::factory()->user->create( [ 'role' => 'administrator' ] ) );
+
+		Deprecation::record_legacy_endpoint_usage( 42 );
+
+		$result = call_user_func( $this->get_site_health_test()['test'] );
+
+		$this->assertSame( 'recommended', $result['status'] );
+		$this->assertStringContainsString( 'Legacy PDF URLs', $result['description'] );
+		$this->assertStringContainsString( '42', $result['description'] );
+		$this->assertStringContainsString( 'page=gf_system_status', $result['actions'] );
+	}
 }
diff --git a/tests/phpunit/integration/Helper/Test_Form_Data.php b/tests/phpunit/integration/Helper/Test_Form_Data.php
index fe6dcea50..36782b867 100644
--- a/tests/phpunit/integration/Helper/Test_Form_Data.php
+++ b/tests/phpunit/integration/Helper/Test_Form_Data.php
@@ -1508,6 +1508,8 @@ public function test_poll_data() {
 	 * @since 4.0
 	 */
 	public function test_empty_fields() {
+		$this->setExpectedDeprecated( 'GFPDFEntryDetail::lead_detail_grid_array' );
+
 		$entry     = $this->entries[6];
 		$form_data = GFPDFEntryDetail::lead_detail_grid_array( $this->form, $entry );
 
@@ -1582,6 +1584,8 @@ public function test_empty_fields() {
 	 * Ensure the Product data calculations are correct when using Euros (or similar comma/decimal switched currency)
 	 */
 	public function test_euro_product_data() {
+		$this->setExpectedDeprecated( 'GFPDFEntryDetail::lead_detail_grid_array' );
+
 		$json                      = json_decode( trim( file_get_contents( PDF_PLUGIN_DIR . '/tools/phpunit/data/entries/all-form-euro-product-entry.json' ) ), true );
 		$json['form_id']           = $this->form['id'];
 		$entry_id                  = $this->gf_factory()->entry->create($json);
diff --git a/tests/phpunit/integration/Helper/Test_Gravity_Forms.php b/tests/phpunit/integration/Helper/Test_Gravity_Forms.php
index 0bb72a6b7..725649844 100644
--- a/tests/phpunit/integration/Helper/Test_Gravity_Forms.php
+++ b/tests/phpunit/integration/Helper/Test_Gravity_Forms.php
@@ -437,6 +437,8 @@ public function test_get_entry() {
 	 * @dataProvider provider_mergetag_test
 	 */
 	public function test_replace_variables( $mergetag, $value ) {
+		$this->setExpectedDeprecated( 'PDF_Common::do_mergetags' );
+
 		// Per-class form titles are dedup-suffixed by GFAPI (e.g. "Simple Form Testing (1)").
 		// Substitute the provider's expected title with the actual loaded form title.
 		if ( $mergetag === '{form_title}' ) {
diff --git a/tests/phpunit/integration/Helper/Test_MVC_Abstracts.php b/tests/phpunit/integration/Helper/Test_MVC_Abstracts.php
index 3fa80d80e..7cad6d3c8 100644
--- a/tests/phpunit/integration/Helper/Test_MVC_Abstracts.php
+++ b/tests/phpunit/integration/Helper/Test_MVC_Abstracts.php
@@ -104,6 +104,8 @@ public function test_abstract_model() {
 	 * @since 4.0
 	 */
 	public function test_abstract_view() {
+		$this->setExpectedDeprecated( 'GFPDF\View\View_Settings::tabs' );
+
 		/*
 		 * Test our load function produces the correct output
 		 */
diff --git a/tests/phpunit/integration/Helper/Test_Notices.php b/tests/phpunit/integration/Helper/Test_Notices.php
index 9907b8975..639221e52 100644
--- a/tests/phpunit/integration/Helper/Test_Notices.php
+++ b/tests/phpunit/integration/Helper/Test_Notices.php
@@ -155,6 +155,33 @@ public function test_process() {
 		$this->assertStringContainsString( '<p>My First Error</p>', $html );
 	}
 
+	public function test_process_state_class() {
+		$this->notices->add_notice( 'My First Notice' );
+		$this->notices->add_notice( 'My Warning Notice', 'notice-warning' );
+		$this->notices->add_error( 'My Info Error', 'notice-info' );
+
+		ob_start();
+		$this->notices->process();
+		$html = ob_get_clean();
+
+		/* A `notice-*` class replaces the default state, instead of being appended to it */
+		$this->assertStringContainsString( '<div class="notice updated">', $html );
+		$this->assertStringContainsString( '<div class="notice notice-warning">', $html );
+		$this->assertStringContainsString( '<div class="notice notice-info">', $html );
+	}
+
+	public function test_process_same_class_twice() {
+		$this->notices->add_notice( 'My First Notice', 'notice-warning' );
+		$this->notices->add_notice( 'My Second Notice', 'notice-warning' );
+
+		ob_start();
+		$this->notices->process();
+		$html = ob_get_clean();
+
+		$this->assertStringContainsString( '<p>My First Notice</p>', $html );
+		$this->assertStringContainsString( '<p>My Second Notice</p>', $html );
+	}
+
 	public function test_html_notice() {
 		$form = 'Message <form method="post"><p><button class="button">Action</button><input class="button primary" type="submit" value="Dismiss" /></p></form>';
 
diff --git a/tests/phpunit/integration/Model/Test_Model_System_Report.php b/tests/phpunit/integration/Model/Test_Model_System_Report.php
index 8b837b893..a16bd9555 100644
--- a/tests/phpunit/integration/Model/Test_Model_System_Report.php
+++ b/tests/phpunit/integration/Model/Test_Model_System_Report.php
@@ -66,7 +66,7 @@ public function test_get_report_structure() {
 		$this->assertArrayHasKey( 'title', $structure );
 		$this->assertArrayHasKey( 'title_export', $structure );
 		$this->assertArrayHasKey( 'tables', $structure );
-		$this->assertCount( 4, $structure['tables'] );
+		$this->assertCount( 5, $structure['tables'] );
 	}
 
 	public function test_move_gravitypdf_active_plugins_to_gf_addons() {
diff --git a/tests/phpunit/integration/Model/Test_PDF.php b/tests/phpunit/integration/Model/Test_PDF.php
index fc1f6f660..23538df99 100644
--- a/tests/phpunit/integration/Model/Test_PDF.php
+++ b/tests/phpunit/integration/Model/Test_PDF.php
@@ -222,8 +222,8 @@ public function test_process_pdf_endpoint() {
 	 * @since 4.0
 	 */
 	public function test_process_legacy_pdf_endpoint() {
-		$this->setExpectedIncorrectUsage( 'GFPDF\Controller\Controller_PDF::process_legacy_pdf_endpoint');
-		$this->setExpectedIncorrectUsage( 'GFPDF\Model\Model_PDF::get_legacy_config');
+		$this->setExpectedDeprecated( 'GFPDF\Controller\Controller_PDF::process_legacy_pdf_endpoint');
+		$this->setExpectedDeprecated( 'GFPDF\Model\Model_PDF::get_legacy_config');
 
 		/* Force a failure */
 		$this->assertNull( $this->controller->process_legacy_pdf_endpoint() );
@@ -814,6 +814,7 @@ public function test_view_pdf_gravityflow_inbox() {
 	 * @since 4.0
 	 */
 	public function test_get_pdf_name() {
+		$this->setExpectedDeprecated( 'gfpdfe_pdf_filename' );
 
 		/* Setup some test data */
 		$results = $this->form_and_entry();
@@ -1340,7 +1341,7 @@ public function test_cleanup_tmp_dir() {
 	 * @since 4.0
 	 */
 	public function test_cleanup_pdf() {
-		$this->setExpectedIncorrectUsage('GFPDF\Model\Model_PDF::cleanup_pdf');
+		$this->setExpectedDeprecated('GFPDF\Model\Model_PDF::cleanup_pdf');
 
 		$form_class = \GPDFAPI::get_form_class();
 
@@ -1559,7 +1560,7 @@ public function test_get_field_class() {
 	 * @since 4.0
 	 */
 	public function test_get_legacy_config() {
-		$this->setExpectedIncorrectUsage('GFPDF\Model\Model_PDF::get_legacy_config');
+		$this->setExpectedDeprecated('GFPDF\Model\Model_PDF::get_legacy_config');
 
 		/* Setup some test data */
 		$results = $this->form_and_entry();
@@ -1590,7 +1591,7 @@ public function test_get_legacy_config() {
 	 * @dataProvider provider_get_template_filename
 	 */
 	public function test_get_template_filename( $expected, $template ) {
-		$this->setExpectedIncorrectUsage('GFPDF\View\View_PDF::get_template_filename');
+		$this->setExpectedDeprecated('GFPDF\View\View_PDF::get_template_filename');
 		$this->assertSame( $expected, $this->view->get_template_filename( $template ) );
 	}
 
@@ -1795,6 +1796,8 @@ public function test_show_form_title() {
 	 * @since 4.0
 	 */
 	public function test_legacy_display_page_name() {
+		$this->setExpectedDeprecated( 'GFPDF\View\View_PDF::display_page_name' );
+
 		$form = [
 			'pagination' => [
 				'pages' => [
@@ -1887,6 +1890,10 @@ public function test_page_break_field() {
 	 * @since 4.0
 	 */
 	public function test_apply_backwards_compatibility_filters() {
+		foreach ( [ 'gfpdfe_pdf_name', 'gfpdfe_template', 'gfpdf_orientation', 'gfpdf_security', 'gfpdf_privilages', 'gfpdf_password', 'gfpdf_master_password', 'gfpdf_rtl' ] as $hook ) {
+			$this->setExpectedDeprecated( $hook );
+		}
+
 		$entry            = $this->entry( 'all-form-fields' );
 		$entry['form_id'] = $this->form( 'all-form-fields' )['id'];
 
@@ -2077,6 +2084,8 @@ public function test_core_template_options() {
 	public function test_handle_legacy_tier_2_processing() {
 		global $gfpdf;
 
+		$this->setExpectedDeprecated( 'gfpdfe_pre_load_template' );
+
 		$settings  = [ 'id' => '556690c67856b', 'template' => 'zadani' ];
 		$entry     = $this->entry( 'all-form-fields' );
 		$form      = $gfpdf->gform->get_form( $entry['form_id'] );
diff --git a/tests/phpunit/integration/Statics/Test_Deprecation.php b/tests/phpunit/integration/Statics/Test_Deprecation.php
new file mode 100644
index 000000000..c50038b49
--- /dev/null
+++ b/tests/phpunit/integration/Statics/Test_Deprecation.php
@@ -0,0 +1,177 @@
+<?php
+
+declare( strict_types=1 );
+
+namespace GFPDF\Statics;
+
+use GFPDF\Tests\Integration\TestCase;
+
+/**
+ * @package     Gravity PDF
+ * @copyright   Copyright (c) 2026, Blue Liquid Designs
+ * @license     http://opensource.org/licenses/gpl-2.0.php GNU Public License
+ */
+
+/**
+ * @group     statics
+ */
+class Test_Deprecation extends TestCase {
+
+	public function tear_down(): void {
+		delete_option( Deprecation::ENDPOINT_USAGE_OPTION );
+		delete_transient( Deprecation::SIGNAL_CACHE_KEY );
+
+		parent::tear_down();
+	}
+
+	public function test_record_legacy_endpoint_usage() {
+		$this->assertSame( [], Deprecation::get_legacy_endpoint_usage() );
+
+		Deprecation::record_legacy_endpoint_usage( 5 );
+
+		$usage = Deprecation::get_legacy_endpoint_usage();
+
+		$this->assertSame( [ 5 ], $usage['form_ids'] );
+		$this->assertEqualsWithDelta( time(), $usage['last_used'], 5 );
+	}
+
+	public function test_record_legacy_endpoint_usage_is_throttled() {
+		$last_used = time() - MINUTE_IN_SECONDS;
+
+		update_option(
+			Deprecation::ENDPOINT_USAGE_OPTION,
+			[
+				'last_used' => $last_used,
+				'form_ids'  => [ 5 ],
+			],
+			false
+		);
+
+		/* A form we've already recorded inside the throttle window is ignored */
+		Deprecation::record_legacy_endpoint_usage( 5 );
+
+		$this->assertSame( $last_used, Deprecation::get_legacy_endpoint_usage()['last_used'] );
+
+		/* A form we haven't seen before is always recorded */
+		Deprecation::record_legacy_endpoint_usage( 6 );
+
+		$usage = Deprecation::get_legacy_endpoint_usage();
+
+		$this->assertSame( [ 5, 6 ], $usage['form_ids'] );
+		$this->assertNotSame( $last_used, $usage['last_used'] );
+	}
+
+	public function test_record_legacy_endpoint_usage_caps_recorded_forms() {
+		for ( $form_id = 1; $form_id <= Deprecation::MAX_RECORDED_FORMS + 5; $form_id++ ) {
+			Deprecation::record_legacy_endpoint_usage( $form_id );
+		}
+
+		$this->assertCount( Deprecation::MAX_RECORDED_FORMS, Deprecation::get_legacy_endpoint_usage()['form_ids'] );
+	}
+
+	public function test_apply_filters_skips_hooks_without_a_listener() {
+		$this->assertSame( 'my-pdf', Deprecation::apply_filters( 'gfpdfe_pdf_filename', [ 'my-pdf' ] ) );
+	}
+
+	public function test_apply_filters_warns_when_a_listener_is_attached() {
+		$this->setExpectedDeprecated( 'gfpdfe_pdf_filename' );
+
+		$callback = static function () {
+			return 'filtered-pdf';
+		};
+
+		add_filter( 'gfpdfe_pdf_filename', $callback );
+
+		$this->assertSame( 'filtered-pdf', Deprecation::apply_filters( 'gfpdfe_pdf_filename', [ 'my-pdf' ] ) );
+
+		remove_filter( 'gfpdfe_pdf_filename', $callback );
+	}
+
+	public function test_get_active_deprecated_filters_ignores_our_own_callback() {
+		$this->assertNotFalse( has_filter( 'gfpdfe_pre_load_template', Deprecation::INTERNAL_FILTER_CALLBACK ) );
+		$this->assertArrayNotHasKey( 'gfpdfe_pre_load_template', Deprecation::get_active_deprecated_filters() );
+	}
+
+	public function test_get_active_deprecated_filters_includes_dynamic_hooks() {
+		$callback = '__return_true';
+
+		add_filter( 'gfpdfe_pdf_template_10', $callback );
+		add_filter( 'gfpdf_rtl', $callback );
+
+		/* The known hooks are always checked; the dynamic ones only on a deep scan */
+		$this->assertArrayNotHasKey( 'gfpdfe_pdf_template_10', Deprecation::get_active_deprecated_filters() );
+		$this->assertSame( 1, Deprecation::get_active_deprecated_filters()['gfpdf_rtl'] );
+
+		$active = Deprecation::get_active_deprecated_filters( true );
+
+		$this->assertSame( 1, $active['gfpdfe_pdf_template_10'] );
+		$this->assertSame( 1, $active['gfpdf_rtl'] );
+
+		remove_filter( 'gfpdfe_pdf_template_10', $callback );
+		remove_filter( 'gfpdf_rtl', $callback );
+	}
+
+	public function test_get_advanced_template_paths() {
+		$this->assertSame( [], Deprecation::get_advanced_template_paths() );
+
+		$gform                       = \GPDFAPI::get_form_class();
+		$form                        = $gform->get_form( $this->gf_factory()->form->create() );
+		$form['gfpdf_form_settings'] = [
+			'abc123' => [
+				'id'                => 'abc123',
+				'template'          => 'zadani',
+				'advanced_template' => 'Yes',
+			],
+
+			'def456' => [
+				'id'       => 'def456',
+				'template' => 'rubix',
+			],
+
+			/* The render path reads the setting case-insensitively, so the detector has to as well */
+			'ghi789' => [
+				'id'                => 'ghi789',
+				'template'          => 'focus-gravity',
+				'advanced_template' => 'yes',
+			],
+
+			/* A PDF pointing at a template that no longer exists has nothing to upgrade */
+			'jkl012' => [
+				'id'                => 'jkl012',
+				'template'          => 'deleted-template',
+				'advanced_template' => 'Yes',
+			],
+		];
+
+		$gform->update_form( $form );
+
+		$this->assertSame(
+			[
+				PDF_PLUGIN_DIR . 'src/templates/zadani.php',
+				PDF_PLUGIN_DIR . 'src/templates/focus-gravity.php',
+			],
+			Deprecation::get_advanced_template_paths()
+		);
+
+		/* Advanced Templating means the template is a v3 one, even when the file carries a v4 `Group` header */
+		$this->assertContains( PDF_PLUGIN_DIR . 'src/templates/zadani.php', Deprecation::get_legacy_templates() );
+
+		/* A trashed form isn't in the user's form list, so there's nothing for them to act on */
+		\GFAPI::delete_form( $form['id'] );
+
+		$this->assertSame( [], Deprecation::get_advanced_template_paths() );
+	}
+
+	public function test_get_signals_omits_empty_signals() {
+		Deprecation::record_legacy_endpoint_usage( 5 );
+
+		$this->assertSame( [ 'legacy_endpoint' ], array_keys( Deprecation::get_signals() ) );
+	}
+
+	public function test_get_signals_are_cached() {
+		set_transient( Deprecation::SIGNAL_CACHE_KEY, [ 'cached.php' ], DAY_IN_SECONDS );
+
+		$this->assertSame( [ 'cached.php' ], Deprecation::get_signals()['legacy_templates'] );
+		$this->assertArrayNotHasKey( 'legacy_templates', Deprecation::get_signals( true ) );
+	}
+}
diff --git a/tests/phpunit/integration/Test_Deprecated.php b/tests/phpunit/integration/Test_Deprecated.php
index be3976dd5..1ab81bf5e 100644
--- a/tests/phpunit/integration/Test_Deprecated.php
+++ b/tests/phpunit/integration/Test_Deprecated.php
@@ -104,6 +104,8 @@ public function test_constants() {
 	public function test_render_save_pdf() {
 		global $gfpdf;
 
+		$this->setExpectedDeprecated( 'PDFRender::savePDF' );
+
 		$render = new PDFRender();
 		$render->savePDF( 'testing', 'mydocument.pdf', 20 );
 
@@ -136,6 +138,8 @@ public function test_render_prepare_ids() {
 	 * @since 4.0
 	 */
 	public function test_common_get_ids() {
+		$this->setExpectedDeprecated( 'PDF_Common::get_ids' );
+
 		$GLOBALS['form_id'] = '20';
 		$_GET['lid']        = '20,21,23';
 
@@ -151,6 +155,8 @@ public function test_common_get_ids() {
 	 * @since 4.0
 	 */
 	public function test_common_get_pdf_filename() {
+		$this->setExpectedDeprecated( 'PDF_Common::get_pdf_filename' );
+
 		$this->assertSame( 'form-50-entry-2091.pdf', PDF_Common::get_pdf_filename( 50, 2091 ) );
 	}
 
@@ -163,6 +169,8 @@ public function test_common_get_pdf_filename() {
 	public function test_deprecated_save_pdf() {
 		global $gfpdf;
 
+		$this->setExpectedDeprecated( 'GFPDF_Core_Model::gfpdfe_save_pdf' );
+
 		if ( is_multisite() ) {
 			$this->markTestSkipped( 'Multisite saves the PDF under a path the prefix glob does not match (known gfpdfe_save_pdf network-site behaviour).' );
 		}
diff --git a/tests/phpunit/integration/View/Test_View_PDF.php b/tests/phpunit/integration/View/Test_View_PDF.php
index aa875989b..9ac40e817 100644
--- a/tests/phpunit/integration/View/Test_View_PDF.php
+++ b/tests/phpunit/integration/View/Test_View_PDF.php
@@ -123,7 +123,7 @@ public function test_show_form_title_outputs_filtered_html_when_enabled() {
 	 * @group slow
 	 */
 	public function test_generate_pdf() {
-		$this->setExpectedIncorrectUsage( 'GFPDF\View\View_PDF::generate_pdf' );
+		$this->setExpectedDeprecated( 'GFPDF\View\View_PDF::generate_pdf' );
 
 		global $gfpdf;
 
diff --git a/tests/playwright/core/system-status/deprecated-features.spec.ts b/tests/playwright/core/system-status/deprecated-features.spec.ts
new file mode 100644
index 000000000..4b3b7ad29
--- /dev/null
+++ b/tests/playwright/core/system-status/deprecated-features.spec.ts
@@ -0,0 +1,162 @@
+import type { Admin, RequestUtils } from '@wordpress/e2e-test-utils-playwright';
+import { expect } from '@wordpress/e2e-test-utils-playwright';
+import type { Page } from '@playwright/test';
+import { test } from '@self:playwright/fixtures/test';
+import { takeSnapshot } from '@chromatic-com/playwright';
+import Pdf from '@self:playwright/utils/gravitypdf';
+import {
+	clearDeprecatedUsage,
+	recordDeprecatedUsage,
+} from '@self:playwright/utils/deprecation';
+
+const TIER_2_PDF = {
+	id: 'aaa111aaa111a',
+	name: 'Tier 2 PDF',
+	template: 'zadani',
+	advanced_template: 'Yes',
+	active: true,
+	filename: 'tier-2-pdf',
+};
+
+test.describe('Deprecated Features', () => {
+	// The signals are site-wide, so the tests share one set-up and run in order.
+	test.describe.configure({ mode: 'serial' });
+
+	let pdf: Pdf;
+	const formIds: number[] = [];
+
+	test.beforeAll(async () => {
+		recordDeprecatedUsage();
+	});
+
+	test.afterAll(async () => {
+		clearDeprecatedUsage();
+
+		// Leave the site as we found it: the PDF is the third signal, and forms outlive the run
+		for (const formId of formIds) {
+			await pdf.setFormPdfs(formId, {
+				aaa111aaa111a: { ...TIER_2_PDF, advanced_template: 'No' },
+			});
+		}
+	});
+
+	test.beforeEach(
+		async ({
+			requestUtils,
+			page,
+			admin,
+		}: {
+			requestUtils: RequestUtils;
+			page: Page;
+			admin: Admin;
+		}) => {
+			pdf = new Pdf(requestUtils, admin, page);
+
+			const form: any = await pdf.createForm('Advanced Templating');
+
+			await pdf.setFormPdfs(form.id, { aaa111aaa111a: TIER_2_PDF });
+
+			formIds.push(form.id);
+		}
+	);
+
+	test('should list each detected feature in the system report', async ({
+		page,
+		admin,
+	}: {
+		page: Page;
+		admin: Admin;
+	}, testinfo) => {
+		await admin.visitAdminPage('admin.php', 'page=gf_system_status');
+
+		const section = page
+			.locator('table.gform_system_report')
+			.filter({ hasText: 'Deprecated Features' });
+
+		await expect(section).toBeVisible();
+
+		// The template of a PDF using Advanced Templating is reported as a legacy one
+		await expect(section).toContainText('zadani.php is a legacy template');
+		await expect(section).toContainText(
+			'Legacy PDF URLs were last requested on January 1, 2025 for form(s) 3, 12'
+		);
+		await expect(section).toContainText('gfpdf_rtl has 1 listener(s)');
+
+		await section.scrollIntoViewIfNeeded();
+
+		await takeSnapshot(page, testinfo);
+	});
+
+	test('should report the detected features in Site Health', async ({
+		page,
+		admin,
+	}: {
+		page: Page;
+		admin: Admin;
+	}, testinfo) => {
+		await admin.visitAdminPage('site-health.php');
+
+		const heading = page.locator('.health-check-accordion-heading', {
+			hasText: 'Gravity PDF functionality that is removed',
+		});
+
+		await expect(heading).toBeVisible({ timeout: 30000 });
+		await heading.click();
+
+		const panel = page.locator(
+			'#health-check-accordion-block-gravity_pdf_deprecated_features'
+		);
+
+		await expect(panel).toContainText('zadani.php is a legacy template');
+		await expect(panel).toContainText('gfpdf_rtl has 1 listener(s)');
+		await expect(
+			panel.getByRole('link', {
+				name: 'View the Gravity Forms system report',
+			})
+		).toBeVisible();
+
+		await takeSnapshot(page, testinfo);
+	});
+
+	test.describe('Dashboard widget', () => {
+		// The dashboard's other widgets carry counts and dates of their own, which would churn the snapshot
+		test.use({
+			ignoreSelectors: [
+				'#wpadminbar',
+				'#adminmenumain',
+				'#dashboard_right_now',
+				'#dashboard_activity',
+				'#dashboard_primary',
+			],
+		});
+
+		test('should count the detected features in the Site Health widget', async ({
+			page,
+			admin,
+		}: {
+			page: Page;
+			admin: Admin;
+		}, testinfo) => {
+			// The widget reports the counts the Site Health page stores once its tests have run
+			await admin.visitAdminPage('site-health.php');
+			await expect(
+				page.locator('.health-check-accordion-heading', {
+					hasText: 'Gravity PDF functionality that is removed',
+				})
+			).toBeVisible({ timeout: 30000 });
+
+			await admin.visitAdminPage('index.php');
+
+			const widget = page.locator('#dashboard_site_health');
+
+			await expect(widget).toContainText(/Take a look at the \d+ items/);
+			await expect(
+				widget.getByRole('link', { name: /Site Health screen/ })
+			).toBeVisible();
+
+			await widget.scrollIntoViewIfNeeded();
+
+			await takeSnapshot(page, testinfo);
+		});
+	});
+});
diff --git a/tools/mu-plugins/gravitypdf.php b/tools/mu-plugins/gravitypdf.php
index cd79e4ee6..87e2cba01 100644
--- a/tools/mu-plugins/gravitypdf.php
+++ b/tools/mu-plugins/gravitypdf.php
@@ -52,3 +52,19 @@ class E2E_Add_On_Bootstrap extends Helper_Abstract_Addon {
 };
 
 add_action( 'init', $addon, 20 );
+
+/* Give the deprecation detection a third-party filter listener to find. The callback is a pass-through, so it
+   changes nothing for the tests that run alongside it */
+add_action(
+	'init',
+	static function () {
+		if ( get_option( 'gfpdf_e2e_deprecated_filter' ) ) {
+			add_filter(
+				'gfpdf_rtl',
+				static function ( $value ) {
+					return $value;
+				}
+			);
+		}
+	}
+);
diff --git a/tools/playwright/utils/deprecation.ts b/tools/playwright/utils/deprecation.ts
new file mode 100644
index 000000000..d5ccb3c5a
--- /dev/null
+++ b/tools/playwright/utils/deprecation.ts
@@ -0,0 +1,37 @@
+import { execSync } from 'node:child_process';
+
+const ENDPOINT_USAGE_OPTION = 'gfpdf_legacy_endpoint_usage';
+const FILTER_LISTENER_OPTION = 'gfpdf_e2e_deprecated_filter';
+
+// Fixed so the rendered date stays put between runs, which visual snapshots depend on.
+const LAST_USED = 1735689600; // 1 January 2025 UTC
+
+function cli(command: string) {
+	execSync(`yarn wp-env:e2e run cli bash -c "${command}"`, {
+		stdio: ['ignore', 'pipe', 'pipe'],
+	});
+}
+
+/**
+ * Record use of the deprecated v3 functionality the System Report and Site Health surfaces detect.
+ *
+ * Options are the only two signals a browser can't set up on its own. The third, a legacy template, comes from a
+ * PDF with Advanced Templating enabled, which the caller creates over the REST API.
+ */
+export function recordDeprecatedUsage() {
+	const usage = JSON.stringify({
+		last_used: LAST_USED,
+		form_ids: [3, 12],
+	}).replace(/"/g, '\\"');
+
+	cli(
+		`wp option update ${ENDPOINT_USAGE_OPTION} '${usage}' --format=json && wp option update ${FILTER_LISTENER_OPTION} 1`
+	);
+}
+
+/**
+ * Stop recording the deprecated usage, so the rest of the suite runs against a site without it
+ */
+export function clearDeprecatedUsage() {
+	cli(`wp option delete ${ENDPOINT_USAGE_OPTION} ${FILTER_LISTENER_OPTION}`);
+}
diff --git a/tools/playwright/utils/gravitypdf.ts b/tools/playwright/utils/gravitypdf.ts
index 08585dc03..b98775ca5 100644
--- a/tools/playwright/utils/gravitypdf.ts
+++ b/tools/playwright/utils/gravitypdf.ts
@@ -53,6 +53,24 @@ export default class Pdf extends GravityForms {
 		await this.navigateToFormSettingsById(formId, 'PDF');
 	}
 
+	/**
+	 * Replace a form's PDFs over the REST API
+	 *
+	 * Used to configure settings the PDF form has no UI for, like the v3 Advanced Templating mode, which is only
+	 * offered when the v3 Tier 2 add-on is installed.
+	 */
+	async setFormPdfs(formId: number, pdfs: object) {
+		const form: any = await this.requestUtils.rest({
+			path: `/gf/v2/forms/${formId}`,
+		});
+
+		return await this.requestUtils.rest({
+			method: 'PUT',
+			path: `/gf/v2/forms/${formId}`,
+			data: { ...form, gfpdf_form_settings: pdfs },
+		});
+	}
+
 	async createPdf(formId: number, label: string) {
 		await this.navigateToNewFormPdf(formId);
 		await this.page.getByLabel('Label').fill(label);