Just out of curiosity, how does Simple Thermostat render your new MQTT HVAC platform?
I tried the 0.86.4 version of MQTT HVAC and, as expected, the operating state is equal to the operating mode. In this screenshot, State and Mode indicate Heat but, in reality, the furnace is not running (it’s idle).
Naturally, this completely screws up a History Statistics Sensor I have that reports total daily heating hours. Given that state=mode, it reports the furnace is heating all day long. Just one of a few reasons I haven’t upgraded from 0.80 yet!