Ahoy there,
I notice the option for full-screen is part of the video player, but what would have been called “Fill browser” in Youtube or “Theater Mode” in twitch is now a magnifying glass in the top right of the video - took me a while to work it out because I was fumbling around with the playback bar on the bottom of the video - didn’t even occur to me to look elsewhere on the player. Maybe either a clearer way of showing that it is that option (as I almost always try to do it with the player interface) or else labelling it a bit more explicitly would I think be helpful.