It used to be useful, but then it "required" Firefox 121+ for some reason (though manually copying the files to ESR115 works).

Bugs:

• There's a bug in the resolution settings that hides anything above 720p.

• The speed override has a bug where it only works for the first video in a playlist and subsequent videos revert to 1× speed. If I can't force an entire playlist at 2.5×, then this doesn't help. 😕