So forgive my ignorance on this, but I am thinking of eventually getting a spare set of wheels for my 4Runner, so I have one for summer and one for winter. This way I could have winter tires permanently on the winter set, and just swap the wheels when winter/summer comes and also wouldn't have to worry about corrosion on the summer set. My question is, does doing this require doing anything with the TPMS sensors? Like does each wheel have a TPMS sensor or is that part of the hub assembly and as long as you use OEM wheels, there is nothing to worry about...? Thanks.

TPMS sensors are in each wheel. If you think about it, putting a sensor in a hub assembly isn't going to tell you the air pressure inside the wheel ;)

For my '22 Sport I got a set of OEM 17" wheels with sensors so I could mount studded snow tires. On my 4R setting up the new sensors can be done from the driver seat. The procedure is in the manual. I don't know what year Toyota implemented this feature.

If your spare is a steel wheel like the one in my 2013 SR5 it won't accommodate a TPMS sensor.

Coolbeans, I see, yes I wasn't sure as I assumed wheels were more simple than that.

I'm not clear why Toyota does some of the things they do. My '22 TRD Sport came with 20" alloy wheels and the spare is identical so it has a sensor and the display shows the pressure in the spare. Oddly, the owners manual states that 4R's so equipped should rotate all five tires. That was news to the service writer when I showed up for the first service. I somehow came to the conclusion that models shipped with 17" alloys have a steel wheel spare. The thing that confuses me it that my '17 Tundra came with steel wheels and it has a TPMS system though it's different in that it doesn't display the pressures. It just flashes an idiot light when a tire is low. Still, it must read the pressures in PSI otherwise how would it know when the pressure is low. My conclusion is that there must be some sensors that should work with a steel wheel spare.
Maybe there is a parts guru around here who cn figure this out.