Fwiw - I have both an LG C2 and a newer Samsung QLED. Neither have ever been connected to the internet, never pester me to connect, and the both turn on right to to my Apple TV

My LG C2 which has never been connected to wifi starts up in maybe 3s. Boots right into my Applw TV and I never have to see LGs software

My personal setup for 4 rooms worth of speakers is a rpi with a Hifiberry hat running debian with Mopidy. I use the Iris plugin for a front end and i mount my music directory via cifs on each pi

+1 for cosmos