That was not my intention. My explanation may have been unclear.
The request is to have an option to treat the heater switch button as thermostat switch instead. The thermostat should exert full control of the heater to maintain target temperature or turn the heater off when the thermostat is turned off, just like a traditional thermostat on/off button.
Yes, that is the intended behavior in this case. The user who enabled this option should be aware that the button is no longer a heater switch but a thermostat switch, meaning the thermostat may turn the heater off.
I propose turning off the thermostat by pressing the heater button while the thermostat is on (button toggles thermostat). This may or may not be while the heater is on, depending on the room temperature. Pressing the button to toggle the thermostat from on to off while the heater is on would turn everything off. Doing so while the heater is off would briefly turn the heater on before everything turns off.
The major drawback is that the thermostat state user feedback is identical for on and off while the room is at the target temperature. The user should know the prior state before pressing the button.
I initially hoped the devs would find a way, which is why it’s a feature request and not an automation; however, after digging deeper I found this thread which explains a way to distinguish button presses from other triggers. If both parent_id and user_id of the event are null, the state_changed event was triggered by the device button. Given this new information, I can achieve the desired result using an automation as opposed to this feature request.