I love this addon i find it useful as it makes browsing less labour intensive. there are a few niggling issues, such as there being two fullscreen buttons when video is playing. this leads to an issue when you press the wrong button in the wrong order and cannot exit fullscreen. another issue i had is i often have to hit f11 every few minutes when an advert plays to enter fullscreen and this requires the keyboard. i can exit fullscreen no problem by hitting the maximize button in top right, but if the addon could make one of the fullscreen buttons in the video map to f11, then i wouldn't need to use the keyboard when swapping monitors or tabs.
edit
I believe i am using firefox nightly, but about says 152.0.6 (64-bit) and neofetch says OS: Linux Mint 22.3 x86_64.
please open a github or equivalent as this site is difficult to log in to.
I managed to fix one my problems with fullscreen, by adding a f11 fullscreen button with the more tools/customise toolbar menu. this means i do not have to use keyboard, but it still leaves the unpredictable behaviour of the buttons in the video area.

the default theater mode for youtube while in using split view or multiple tabs on the same monitor is garbage, making it like twitchs is top tier, made an account just to review. thank you