Personally, I just installed another launcher for my shield (projectivy launcher) so I don’t have to deal with annoying advertising. You could also replace the stock OS with a foss android TV, but I haven’t tried it myself so I can’t tell you if it works well or not.

If it is in two different houses, why would you use a NAS as a client for jellyfin ? You’d better connect an android TV box like an nvidia shield and connect to the jellyfin.

Of course, the jellyfin instance should be accessible over the internet, either by setting up a reverse proxy or a VPN.