Install the Always visible userscript (needs Tampermonkey, Violentmonkey or similar), reload, then switch tabs. With the script, Detections should stay empty.

Breakage checks (run with this window focused)

Manual:

Manual: hover me: turns green, back to normal when you move off

Manual: Open popup & check it is patched

Suppression checks (PASS only with the script active)

Synthetic events the script must swallow. Without the script these all FAIL — that is expected.

Detections

DETECTED = the script's disguise failed. GAP = a path the script never covers; these can fire even when it is working.