@Steve2121 If you're stressed about the Uberturbines just swap them out for smaller wheels and call it a day. That's what I did, I ordered 18x8.5" ET35 wheels for my M3P before I even picked up the car.
Years ago I went through fighting Tesla to replace a cracked 21" wheel on my S, a very similar big cast wheel + thin sidewall tire (245/35R21) as the M3P setup. Also tires for bigger diameter wheels are more expensive, it doesn't take many tire replacements to pay for a basic set of smaller wheels. We downsized the S to 245/45R19 and never looked back. Same thing with our new M3P, downsizing from 235/35R20 to 245/45R18.
Are you going to have pinch flats and cracked wheels all the time with the Uberturbines? Probably not. Overall you'll be fine, but yes it may happen, and it's definitely more likely with the Uberturbines than if you downsize to get some extra sidewall. If you'll be really annoyed at life / your car / Tesla / Elon Musk / whomever because you got a flat or cracked wheel that probably wouldn't have happened on 18s, then go ahead and swap to 18s
before that happens.
Note the OE Model 3 18" wheels do NOT fit on the M3P (or so I've read, I never tried). There are aftermarket options though, some machined specifically for the M3P stepped hub, and others that just need a centering ring or 3mm (I believe) "step delete" spacer.
I'll also mention that downsizing the wheels was actually a handling
upgrade for me, which I wasn't expecting. I was expecting slightly more grip based on my tire choice - I actually got quite a bit more grip (Potenza Sport vs OE-spec PZ4) - but what I didn't expect was how much better the M3P feels with the lighter 18" setup. The ride is a little smoother of course, that is expected, but it also feels more nimble in quick back-and-forth turns, and the power steering feels better, almost like it was struggling before with the weight of the Uberturbines.
Note older M3P like
@jjrandorin's came with different 20" wheels and tires. I believe those wheels were not quite so heavy as the Uberturbines, and the old OE tire selection (Tesla-spec PS4S) are widely considered better than the new OE tires (Tesla-spec PZ4), so on an older M3P there's probably less handling benefit to be gained just from downsizing wheel diameter. (But maybe still some?)