Insteon.

When combined with a Universal Devices hub it’s great. Been running my house on it since 2012 without issues other than the short insteon shutdown scare.

Trivial to get it all working with home assistant as well with the benefit of the scenes being programmed into the devices and thus they work instantly.

https://www.insteon.com/

https://www.universal-devices.com/store

Working on this myself at the moment.

Mitsubishi2mqtt and Esphome-mitsubishiheatpump are what I am trying with Home Assistant . Leaning toward the esphome integration.

Op should checkout Hacking a Mitsubishi heat pump for more details but be warned that the latest Wemos D1 Mini’s don’t seem to communicate with the Mitsubishi (at least I couldn’t get them to).

Have some esp01s coming which I hope will work.