It works! I love it! However, the black fonts in a video thumbnail are a bit dimmed.

Works precisely as expected with the classic layout <3

work

Does exactly what it needs to - great experience!

Use that one!

С задачей справляется.

Works
No problems
(Firefox App Android)

i don't have the option to choose between A and B (maybe due to Classic Youtube?), but A is close enough to KDE Breeze dark to be pretty and the Addon itself is working flawlessly - immediate theming, not a delay with bright white page after loading as with some other YT-theming.