Highlight third parties with unload event handlers?

Would it be possible to highlight third parties that still rely on unload event handlers?

Those break the back/forward cache on some browsers, and are unreliable on other browsers or mobile platforms.
There are better alternatives available which don't have these downsides (e.g. visibilitychange).
More details in this lighthouse issue.

We did a large outreach to increase awareness and successfully convince lots of third parties to migrate away from unload event handlers, but there is still a long tail of third parties... Perhaps, thirdpartyweb could help raise awareness at scale?

Here is a query that should give a list of unload event handler sources:

SELECT COUNT(*) AS CNT, unload_source, unload_line, unload_column 
FROM `httparchive-lighthouse.BestPractices.unload_sources`
GROUP BY unload_source, unload_line, unload_column 
ORDER BY CNT DESC LIMIT 1000;

The payload names no repository files, tests, or entry points. Start by reviewing the linked Lighthouse issue and running the supplied BigQuery query; before implementation, define where third parties with unload handlers should be highlighted and what output demonstrates completion.