Buffers the video without autoplaying and puts it in HD if the option is on. For Firefox, Opera, & Chrome
< Отзив за YouTube Auto Buffer & Auto HD
Are you using the beta?
No, I'm using version 1.2.87
Well, the beta has some good improvements you should try, until I release a new official version.
Not always working
When set 360p and Disable DASH Playback is selected - work, but when set 360p and Disable DASH Playback is unchecked - not work. After few seconds 360p change to 720p automatic or 240p automatic and video not work.