Greasy Fork is available in English.
Зменште енергоспоживання браузера за допомогою неявного затримання планування
You can try https://greatest.deepsurf.us/scripts/473972-youtube-js-engine-tamer and https://greatest.deepsurf.us/scripts/469878-youtube-super-fast-chat
For this script, I do think it will make cpu usage 100%. but anyway if this happens then just uninstall this script.
this script will cause bug with Youtube sometimes, which will make cpu usage 100%