I am SO done with YouTube's abysmal ways of doing things as they want to.
Thanks tons.

Наконец-то 4к видео можно смотреть.

to działa świetnie ssam tego używam i bardzo pomaga w starszych komputerach

Awesome!! It works perfect

:)

Great for old laptops! Reduces battery drain with lowering the CPU usage as this add-on forces the video in YouTube to play with h264 instead of fancy VP9.

Also you want to block 60fps? - You're in!!!

Solved the video stutter issue caused by forced 60fps on 720p and higher definition videos on YouTube after enabling the "block 60fps video". Thank you.

I've checked the source code on the provided github link and it looks clean.

I would recommend recommending this to anyone having the same issue.