This is literally already a feature on samsung’s OneUI, I use it to watch movies with the wife on airplanes and the like. Sync issues between bluetooth devices would only be a problem if you were trying to use it for like a surround system or something.

Won’t matter that much for just sharing music/tv/movie/youtube with a friend in public

I haven’t enjoyed any other mobas, but I’ve put ~100 hours in to this one. The comeback mechanics seem fine enough, I’ve had a few games that have come back from a ~30k soul difference.