The issue with the Subaru TPMS is that the car can only store sensor data for one set of sensors. I know that other cars have the ability to store multiple sets of sensors, but Subarus can't. The reset tool that works with these is different from what I understand than the conventional (and cheaper) ones that the tire places sell, forcing you to go to the dealer to reset it every time you switch wheels, given that you have sensors in every set of wheels.
You could always just ignore the light, tape it (as mentioned above) or give it a name. I call it the "winter tire light" in my Mazda. 
