I have ST and an Ecobee3. I’d like to have Ecobee turn on the air handling unit (AHU/fan) when the remote sensor and fan reach a high enough mismatch. This will prevent overcooling/overheating one room when the fan could just mix the air between the two rooms.
ecobee3 “circulation mode” is a good feature to just turn on schedule, 2-3-4 -5 minutes every hour. Without depending on ST or internet. It does increase your motor starts count and increase the motor wear a tiny bit - the benefits should be increased circulation, less humidity in basement, closer temps from room to room (assuming the distribution is balanced) .