I also have YT premium. On desktop, I use firefox and the popout video feature. It is easily resizable and movable. Downside is that js-player controls still show on the webpage, not the popout. On ios, once paused, just tap anywhere on the video anywhere there isn't a widget. That hides all the video controls for me.

Edit: Also there are keyboard controls for going frame-by-frame, if you need that much control. Or there was last time I used it a long time ago.