Blocking: Escape closes the listbox but doesn't clear tempValue. Repro: arrow-navigate to an option (sets tempValue), press Escape (intending to cancel), then click away — onBlur sees tempValue is still set and commits it as the new value, overriding the user's intent to cancel.

Add tempValue = null here:

} else if (e.key === "Escape") {
    open = false;
    activeIndex = -1;
    tempValue = null;  // discard keyboard navigation on cancel
}

Non-blocking: aria-owns alongside aria-controls referencing the same element is redundant. The ARIA 1.2 combobox pattern specifies aria-controls to reference the popup listbox — aria-owns is only needed when the DOM parent-child relationship doesn't match the desired accessibility tree structure. Since the listbox is already a descendant of the same combobox widget, aria-controls alone is sufficient. Consider removing aria-owns.

Non-blocking: The listbox is now always in the DOM (the previous <if=open> guard was removed). AT visibility when the combobox is closed now depends entirely on the skin CSS using display: none for .combobox__listbox when .combobox--expanded is absent — display: none correctly removes the element from the accessibility tree; visibility: hidden or opacity: 0 would not. Worth confirming the skin CSS uses display for this toggle.

Non-blocking: The previous revision had SSR snapshots for floatingLabel and Filtering (autocomplete='list') modes — they were removed here rather than replaced. The snapshot count is now 6 cases vs. the prior 8. Consider adding:

it("renders floating label", async () => {
    await snapshotHTML(Default, { floatingLabel: "Campaign" });
});
it("renders filtering variant", async () => {
    await snapshotHTML(Default, { autocomplete: "list" });
});