exten por 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 :)