Can you only buy the LR with staggered wheels? No squared option?
I'm not sure if the wheel arches are flared for *both* the Plaid and the LR, but if the LR wheel arches are the same dimensions as the 2012-2020 S, you may struggle to fit a 255 tire in there without rubbing, especially if you're putting them on the 10" wheels from the rear and then rotating that to the front. But maybe not, as I'm not sure what sidewall profile or wheel size you're looking at and that plays in as well. When he gets the car, he can take some measurements and we can help get it all figured out.
If I was you, my suggestion would be to keep the staggered wheels with the recommended tire widths, and just have a tire shop swap the tires across the axle (left to right, not front to back) once at about halfway through their lifespan. That way you get full use of the tire even if there's some camber wear in the rears. Tesla is super finnicky about denying warranty coverage where they can, and I guarantee that if they found you running your rear wheels in the front with stretched tires, they'd duck out of any suspension warranty claims you made.
Other question is - what about tire life warranties? I've never used them, but heard of folks on this forum who get, say 15k miles out of a tire that guarantees 30k miles, file a claim, and use the refund to partially cover new tires.