I did a quick search (here and on LGT) and posted over on LGT.
I just grabbed my summer (3-season)/track wheels and tires from another NASIOC member. I want to run them for 3-season use, at least until I wear out the tires or get some dedicated track wheels. I don't want to live with the TPMS light all of the time, but I don't want to pay to have the TPMS moved back and forth, nor to have 8 tires dismounted/remounted to move the 4 sensors.
Some junk yards will pull all 4 sensors and the computer. Are there any Subaru TPMS sensors that are NOT compatible with our brain? While I am at it, are there any other vehicles (other brands) whose sensors are compatible with the system that we have (assuming, of course, that they are properly reprogrammed)? I also see that TireRack sells TPMS sensors- do those work with our brains (again, assuming a reprogram)?
Just some info from LGT (that I did not see when I searched over here)- You can also put a set of TPMS in a second set of wheels and get a second TPMS controller and have those 5 components all programmed. This allows you to swap wheels AND the controller, to avoid the issue of having to either transfer the sensors or have the receiving unit re-programmed to accept different sets of TPMS sensors every time you switch wheels.