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...

For some reason the sharpness/richer colour is more noticeable in its chrome version.
That stated IT HAS NO CONTROLS, none are shown in the preview panels. The detail sharpened is as it at very small 1x1 or 2x2 level.
Since at the moment of this post there are no free add-ons that sharpen VIDs this is best.
My hope is that a 2x tick box is added.

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