The main question: what is your favorite temperature sensor without paints, preferably using wall power? Interested both inside and outside.
Auxiliary Question: Have you tried configuring automations that will open and close the blinds based on indoor and outdoor temperatures? Looks like it could be an effective way to control heating costs. Cellular blinds can be good insulation, so you may want them to be closed when it is cold and dark, but the fact that it is automatically opened on the south windows, when it is cold indoors and in daylight could be helpful.
Auxiliary grease: why the hell is the Mysa thermostat not registered as a temperature sensor? Obviously, it measures the temperature! Obviously, it is already communicating with HomeKit!