Unfortunately I have to put this note, so that they can try to fix the problem. The extension causes a huge delay (LAG) to several videos, for no apparent reason. It's literally impossible to Pause, Play, Like, Dislike, Show Comments, See Infomations, Etc, without witnessing a GIANT lag, looking like the tab stopped working

Developer Response: I ran the tests again using only the extension in Firefox, logged into my Youtube/Google account, based on the video: https://www.youtube.com/watch?v=-54NQ-VQoG4, but it doesn't happen exclusively to that. The problem persists. For "extra" reasons, I don't intend to reinstall the browser just to test the extension, but everything works fine without the extension. It could be an isolated case.

PS: I'll change the review since you saw the post. But I still have the problem.