The "Supported Sites" list is a joke. It is a list of sites where one version may have worked at one time in the past. It is not an updated, accurate, tested, or supported list of sites that work. Of course the list is impressive if any site that works even for one visit gets added then never removed when it does not work.

It is False Advertisement at best and fraud at worst. There are many sites that have been broken for 4 or more years. The response on the Google Group that is support channel for this is "something must have changed on the site" but no fixes most times. That is NOT supported. Both the Legacy XUL (6.3.3) and WebExtension (7.6.0) versions are broken on many of these sites and both version should have been fixed. Some of the sites were posted as far back as 5+ years ago; As such both versions should be fixed!

Don't advertise what you don't support, especially while asking people to PAY.