Oh the suffering of... running one program in the basement with the usb thing, and running a different program to view everything?

If it caused any difficulty at all to use different viewing programs on their different boxes, it would be trivial to cut down to one. If using NAS network storage caused problems, it would be trivial to remove it. And they're running kubernetes entirely for fun, making it the opposite of "have to maintain".

The part that actually makes this system tick is quite low maintenance.

To your point though, a simple box you plug in that "just works" would be nice for the rest of us. (Yeah, not an Apple TV though and nothing with a subscription.) Perhaps someone has already done something like that on GitHub.

I've been very happy with Kaffeine, installed on my regular desktop PC, for recording shows.

https://apps.kde.org/kaffeine/