I waited months for Google to release a firmware patch to unlock Bluetooth. Eventually, I got tired of 4 mostly bricked (could still use them wired) controllers laying around and tossed 3 of them. I wish I would have kept them all now, Stadia controllers are some of the best, I may have to pick up another one online.
If you’re using Android, check out xmanager. It’s basically a free cracked version of Spotify Premium.