I have been running Bazzite on my TV for a few weeks. Was using PopOs however I was having issues with some games not launching, probably to do with the combination of Unraid VM, GPU passthrough, Xorg with fractional scaling on a 4k pannel. Bazzite with "Game mode" is amazing. Closest thing to Steam OS that I know about. Everything just worked with the exception of needing to firmware update my xbox controller to get it to work. Game mode seems to report as a steam deck.
I believe the only way to firmware up an Xbox controller is on an Xbox or through the Xbox Accessories app on Windows. I've been using my work laptop to update my Xbox controllers.
As an alternative, some of the 8bitdo controllers are in LVFS, and I've heard the PlayStation Controller Firmware Updater works in WINE for DualShock and DualSense controllers.
Highjacking your comment to mention the 8bitdo Ultimate 2C, for anyone looking for a 8bitdo controller
Haven't personally tried it yet, but LTT made a video about it and price, quality and features seem all pretty good.
https://www.youtube.com/watch?v=3N5MlZg_Cdg
I also haven't used the 2c, but the older bt+usb2.4 ultimate still can't be configured in linux and the android app seems to not work at all.
I like the 8bdo controllers but being able to remap and set deadzones would be nice, and I'm waiting for steam controller 2 at this point. hopefully they do hall sticks.