This extension works great, particularly with the configurable keybinds to control speed, and to seek.

One of my favourite features is the ability for this extension to affect advertisements in youtube.

My most common use for this extension and the reason for downloading it is to speed up videos past 2x speed (most commonly to watch lectures at 4x speed).

However, on my M2 MacBook running Sonoma 14.3.1, Firefox version 123.0, this extension often takes up 2-7GB of RAM. This is not an issue on my Windows 10 PC. I'd assume this is due to a bug causing the video cache to not be cleared often enough.