Greasy Fork

Issues

Ps: i tried it on:
-palemoon
-signed off youtube

Only v2.0 works well & video is centered with comments..
but the height of the video is "slightly" cut or reduced

Test the version 3.2. I think I solved the problem. Thanks for reporting. Anyway, I believe that other scripts (such as "YouTube Center") or user styles should prevent "Youtube floating player" to work correctly.

3.2 doesn't work, only 2.0 on palemoon.

by the way, do you think you could write such script:
what i'd like:
a script to intercept my last choice on the playlist button, either i restart, either my browser crashes, either i delete temporary files, that's why i thought about having the choice saved in a file of my browser's profile.

I also saw the addon:
https://addons.mozilla.org/en-US/firefox/addon/nextvid-stopper-for-youtube/
but i don't want one toolbar icon just for youtube, cause i have enough icons from other addons, & it's not great to have a toolbar icon while not having any use of the
youtube icon to disable & enable it on the page. maybe you could make a workaround of this addon that would allow the effect to work directly on the youtube button. i don't even know if this addon works as expected anyways "either my browser crashes, either i delete temporary files"

I'm sorry, but my knowledge is limited. I have no way to write the script you seek.