On the Model 3, we were able to change TPMS before the "reset sensors" button was added. In fact, I've found that the "reset sensors" button doesn't seem to do anything useful.
If you just swap wheels/tires/tpms on the vehicle and then start driving it, the car will give a TPMS failure warning. After a day or two, the car will automatically discover the new TPMS sensors, and pop up a dialog asking you to select your wheel size. I would assume that the Model Y will work in the exact same way. It would have saved you all the effort of breaking down the tires to swap sensors.
Sorry for the late reply, haven't check the forum in awhile.
I paid $75, split with the person I swapped with. And yes to balancing. The shop is in Fremont next to the factory and they do a lot of work on Tesla so they had pads. I recommend having a set of pads though.
Definitely get a set of lifting pads to keep in the car. I got a screw in my tire and my normal tire shop couldn't fix it because no pads. They usually fix flats for free for their regular customers. (Been one for almost 30 years). The America's Tire Center was a zoo. So I called Tesla and they were able to fix it at the local service center but it cost me $87.