Tip: Change video playback speed on Learn (and most other websites that dont allow it)

document.querySelector('video').playbackRate = 1.25

Simply paste this into your browser console, replacing 1.25 with whatever your desired speed is. i.e 1.00, 1.50, 2.00

You can access the browser console by pressing F12 in Chrome and Firefox, and Option + ⌘ + C in Safari.

Cheers!

Edit: I am also told there is a chrome extension that can do this https://chrome.google.com/webstore/detail/video-speed-controller/nffaoalbilbmmfgbnbgppjihopabppdk/related?hl=en