I thought I'd throw my $0.02 in here about this issue. The AppleTV's onboard storage is intended for apps and cache; if you start putting very many media files on there you'll fill it up quickly, and anyway tvOS will delete those files when it runs low on space for apps and cache. As far as VLC, Plex, and Infuse are concerned - I was a long-time Infuse user, but I finally decided to try Plex, in part because of its library-sharing features. Once I got Plex set up (not the easiest task, and I'm sure I still have things that could be tweaked a little, it really is a complex piece of software) and tried it out for a while, I cancelled my subscription for Infuse (which was up for renewal soon - it's great software, but overpriced for what it is) and switched to Plex. As for VLC, I've never used it on my AppleTV. I've used it sometimes on various Macs I've owned, but I've started to have some serious issues with it on my MacBook Pro (M2) - both the current Apple Silicon and Universal builds of VLC have started having problems playing videos for me. I've seen a lot of praise for IINA here, so I'm going to try that.