thorny ledge
Whenever I try to register my watch to my home assistant instance, I just get a message on my phone saying "Could not register watch".
I have a Pixel 7 Pro, and a Google Pixel Watch 3, and my Home Assistant instance is self-hosted running behind tailscale with self signed cert, I can access my instance just fine on my phone directly.
distant leaf
Wear OS doesn't easily allow you to import self-signed certificates so for now you're out of luck. A valid SSL connection is required if you use SSL. You may want to follow this issue for possible updates in the future: https://github.com/home-assistant/android/issues/3739
Also note that the watch may or may not use your phone's connection, so if Tailscale is required to reach your server updates may not reach your server at all depending on how the watch decides to send/receive data.
thorny ledge
Since I only have the wifi model, I'd expect it to just use my phone for network connections. I'll give it a try with a proper certificate though, thanks!