I’d gladly replace Android with any flavor of Linux whenever possible. But the phone and TV set top industries make it difficult/impossible. And the next barrier is whether my family could operate these without patience for bugs and missing features.
I’ve been transferring files from old NTFS drives formatted for Windows on a Debian machine without issue.
You could host something like IPTVnator on your Proxmox server: https://github.com/4gray/iptvnator
Is freemediaheckyeah an IPTV service? Plex or Jellyfin can manage IPTV streams. Plex needs additional software (e.g., xTeVe) to take an m3u playlist and convert it into a tuner.
https://blog.iptvinsider.com/watch-iptv-on-plex/
https://jellyfin.org/docs/general/server/live-tv/setup-guide/
I use metube and Pinchflat.
Metube is great for one-off video downloads and works for many sites including social media. This comes in handy a lot when I want to send a short reel to friends without linking to Facebook, etc.
Pinchflat automatically downloads my favorites playlists and a couple other channels that I follow. These videos go into specific folders that are linked to Plex libraries.