Ecobee Smart Thermostat- Using Room Sensor as primary control
I have two of these thermostats installed.  When you set a programed time for the thermostat, you can also select which sensor is active during that time.  For instance, I have a sensor in the bedrooms and one in the main living area and then the thermostat itself.  The thermostat is in an odd location and I don't like the temperature it ends up reading.  So, for our "daytime" program, I have only the main living area sensor active.  The system doesn't care about the other two temperatures and just turns on and off to make sure that one sensor is happy.

For the "sleep" part of the schedule, I have the two bedroom sensors active, so the temp of the main living area doesn't matter.  I had a problem with one bedroom getting warmer than the other, but adjusting the dampers on the vents in the room corrected that so the rooms warm and cool at about the same rate.

There is also a setting to ensure the fan comes on for a minimum amount of time per hour.  This can be set so the air circulates even if the active sensors are at the "correct" temperature.