Greasy Fork

Really good, it was works perfectly. Now no more hang or lag when open multiple tabs, youtube vidoe and high work.

Could you try to downgrade this script to see any improvement?

https://greasyfork.org/en/scripts/431573-youtube-cpu-tamer-by-animationframe/versions

Sorry, that might have been my mistake, my sentence was bad. My bad! What I mean is that it works perfectly! Before using this script, I couldn't play YouTube videos while doing heavy computing tasks, but now I can. It’s been really helpful—thank you so much for your work!"