This is a pretty great addon but it doesn't seem to work with the 1080p premium encode.

I want an extension that lets me choose which quality I want! I'd like all videos in 320p, can you implement that? Thanks

For some videos, the quality goes up to 4K, for example: https://www.youtube.com/watch?v=ys3x43wtuJQ

Console log:
19:11:25.243 sfeerf = Object.assign(sfeerf, JSON.parse('{"hd":true,"quality":"hd1080","log":true}'));
inject.js:120:3
19:11:27.209 YouTube HD:: getAvailableQualityLevels returned empty array
videos:19:15
19:13:36.858 Loading failed for the