Hi,
I understand that you contributed to my DTH (My Ecobee device).
If you want to use only certain temp sensors for your colder/hotter rooms at different times of the day, then you can use ecobeeSetZoneWithSchedule smartapp which can create virtual or physical zones (with smart vents) in your home. The avg calculation can then be done on your choice of temp sensors by creating a zone which can be enabled at certain times of the day.
http://thingsthataresmart.wiki/index.php?title=EcobeeSetZoneWithSchedule
You should look also look into smart vents.
EcobeeSetZoneWithSchedule is available at my store:
http://ecomatiqhomes.com/store
Regards.