I’ve been considering the same thing. I’ve recently bought a load of their switches to replace the Hue dimmers I had, and also get rid of a lot of smart bulbs.
All my window contacts and motion sensors are Xiaomi too. I then read that they had local execution, which is awesome! I’d love it if there was a way HubConnect could work with them directly rather than via Homebridge. I’ve had pretty much zero success with getting that working. But the Xiaomi hub is not out of the picture yet. I’ll have one more go at getting some stability, if it fails, I’ll be going for their hub