Tested in YT, Do absolutely nothing apart accessing own data !!!! At least put some more instructions of your addin because nothing appears & no controls to the video are available. If U intend to do some filtering automatically without manual intervention, please write it better in your description.
In any case, no video improvement is notable. Can U specify a sample video url where I can see something tangible?

in Chrome, this Add-On works perfectly fine, just switch and forget about it. But in Firefox (Flatpak) is no change at all. Therefore this Add-On is totally use- and senseless, sorry...

No control bar appears when switching-on extension, like it is shown in description...
Thus, no ability even make a try any of the effects... :(

Не работает