I have no practical experience with motorized dampers. What I do know is that you need to ensure they don’t overly impede air-flow (like making a programming mistake in Home Assistant that causes all dampers to close) to ensure you don’t unbalance the HVAC system (i.e. your furnace becoming unable to push the air it draws because too many dampers are closed).
FWIW, the remote sensors I mentioned are a means of improving how the thermostat measures indoor temperature. For example, maybe the thermostat is mounted in great spot to see/access/control it but a lousy spot for measuring your home’s ambient temperature. You can install a remote Smart Room sensor (temperature and motion) in an optimal location and instruct the thermostat to use it for measuring indoor temperature.
Alternately, you can install several Smart Room sensors and instruct the T9 to use the average of them or just the rooms where you are active and motion is detected (because the Smart Room sensors also have motion detection).
Because the thermostat communicates via the HomeKit protocol (over Wi-Fi), Home Assistant is immediately informed of all of the thermostat’s activities including when motion is detected in a given room and the room’s temperature. So if you want to create automations based on presence or room temperature, the Smart Room sensors will provide that for you.
The nice thing is that all of this remote-sensing temperature control works without Home Assistant. In other words, if you want to use Home Assistant to control your HVAC system to a finer degree (such as with dampers) you certainly can but in the event your Home Assistant server is offline, the thermostat still does its job according to how you configured it. This adheres to my personal philosophy of “interconnected but independent islands of home automation”; everything continues to perform the basics (lighting, security, HVAC) even if the home automation server is down.