OK @Dr. Hax, I decided to take a stab at supporting heat pumps (building off the unreleased v1.5 image). It's a beast. So many rules need updated... heating, cooling, fan, humidity, hot water, sensor/setpoint changes, all the checks and protections, the initialization routine. Those are just what I found so far, there are probably more. 😮‍💨

When I'm done, I'm going to need a lot of help testing this, and not only with heat pump systems. This will require full regression testing for HVAC and EU (aka generic) modes too.