Worked fine for a long time and I already forgot that this annoyance exists.

Recently it broke Media Keys however (both about:config settings TRUE). When not in focus in some burried tab, sometimes with another application in focus, play/pause quickly reverts making the play/pause media button useless. Clicking on the Win10 overlay which then pops up also quickly reverts back to the play/pause state it had before. Works when I'm on the affected youtube tab again and breaks easily when it's a burried tab again. Was looking everywhere on why the media button broke for my win10/firefox recently, but it's fixed with this addon deactivated.

It's was a really great add-on but it needs to be updated for the new YouTube. I doesn't work at all now.

Works wonders on the desktop version but unavailable on the mobile version, otherwise a 5/5 add-on.

Autopauze still happens in fullscreen-mode

It does start the video a split second after the video is stopped by the auto pause.
I would recommend, if possible, having it work on the first pop-up that states "video will pause soon", rather than the second pop-up that actually stops the video. If that were possible the annoying split second pause would be eliminated, rendering the add-on flawless and garnering a pay-pay donation from me.
But this is definitely the best option I've found.

makes my computer slow