On android quality works but video speed does not.
Also, "Access data for all websites" is a privacy risk. I understand it is required to enable the extension for embedded videos but since this is not the most common use case for many, an option to disable this permission and only let it access youtube.com would be welcome.

Good

Expanded mode does not fill the viewport, "Full page" overflows the viewport cutting off parts of the video, including playback controls and the scrobbing bar.

Pretty handy!! Works on Android too 😁✌️

This addon causes random redirections to Youtube community posts every now and then. Can you please fix it? It's quite annoying.

Would have been nice, but random redirects to community posts instead of videos are annoying.

5 stars if video speed works on embedded videos.

This used to be a good addon, and lots of it's features are super useful, but it CONSTANTLY redirects you to a random community post instead of whatever video you click, this happens daily for me at least half a dozen times, I'll gladly change my review once this annoying (and judging by all the other reviews, extremely common) bug is fixed.

THe PC version works well enough, no complaints there. But the Android version for Firefox (84.1.1, Build 2015781795) is useless since I can't find any way to change the settings.
And since it looks like the developer has abandoned this and there's no support on his webpage, my 2 stars are being generous.