Chrome has an amazing feature that allows you excecute a JS funciton as one of your bookmarks. Someday, when I was watching an YouTube video and wanted to play faster than 2x (podcast video related), I can't. So I created those two scripts and passed them as bookmarks saving in my bookmarks bar.
Now, whenever I want to play a video faster than 2x, I can and I can pick speed or return to normal speed.
Disclaimer: Use it with moderation. I just go for 3x or 4x speed.