If the publish the API for the server, as well as allow the device to specify the API hostname to connect to, that's all I need. We can write our own server implementation fairly easily, and this saves us the hassle of having to reverse-engineer the API, plus makes setup much easier if we can just tell the device where to connect.

I wish more manufacturers would unlock their devices for local use when they don't want to support them any more. Or maybe even, hear me out, before support ends! Maybe we could even vote with our wallets and buy open stuff instead of walled gardens.