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Not a complete answer to your question but here is a little info.
i purchased a BMW X 5 compact spare to use with my Model S cars. I have used it a few times with no problem. I think the S and X use the same bolt pattern. I haven't had time to pull wheels and compare but plan to. Elon had 21's on the X at the reveal. I assume they were Model S wheels. They likely put them on because they did not yet have grey or black wheels in 20 and 22. They looked sharp on a black X.