Finally smth that WORKS! I am long, long time Linux user and I tried:
- without any YT addon - works like sh^&*(%
- h264ify
- enhanced-h264ify
- refined-h264ify
and even [what I initially thought it will be best]
- 'Improve YouTube!' <-- biggest hangs, slow downs, lags etc.

Only this addon work as it should. Thank you and keep it up!

make chrome version PLS

Works great on firefox nightly and embedded videos. It saves energy and processing power by offloading video decoding to the more capable and efficient GPU.

works great.
thanks for update!

Works great.

Great thanks to your work wsiegenthaler.
Everything work like charm.

In my experience h264ify-embed-fix work better than h264ify and enhanced-h264ify.