exten — tuvrai

It was tested on various video sites and it does work on youtube, bitchute, invidious instances, and more. It can also work with audio only media (not guaranteed).

Instructions:
v - increases speed by 0.1 (0.5 when shift is down)
b - decreases speed 0.1 (0.5 when shift is down)
the speed range is 0.1 - 16.0
e - pauses video and opens new tab with embedded video (useful when the video is age restricted)
Shift + {1,2,3,...,0} key - goes forward in video by given amount of seconds (0 means 10), when alt is down it goes backwards instead.

Happy for suggestions :)