You can only swipe down to minimize a video if it’s the first video in a playlist (or not part of a playlist at all).
That seems really daft. Things like swipe gestures work on muscle memory - but if you have yo also consciously remember whether what you're watching is in a playlist or not, it's much less intuitive.
I like swipe down to minimise and use it a lot. This feels like it could be a real pain.