It's just me or recently (couple of days or so) with the Dark themes, when you open a video, all the main text is black, so totally unreadable?¿ Besides that, great add-on. Sometimes get frozen after harcore usage and days without closing ff, but I thing is more related with the browser.

If you use enlarged player that covers the whole viewport and scroll away, there's no option to perfectly focus on the player again. I wrote this simple JS, so when you middle click anywhere on the page it scrolls right where the player is (should add some functionality that allows that by default in your addon)

document.getElementById("content").addEventListener("auxclick", function(event){
if(event.button == 1)
document.getElementById("player-theater-container").scrollIntoView();
});

Отлично

Good enough extension. I note that the Auto-pause for the background tabs, doesn't work. Pause videos on the backround tabs, when a video in the foreground tab starts, works fine.