Sooo I was just looking and in Europe, the X5s and X6s also had another brake option (385x36) that "should" be a direct fit on the F10s:
This is the Caliper that is bigger than the 760i/750i (EUR) caliper but smaller than the X5m :
https://www.realoem.com/bmw/enUS/sho...diagId=34_1584
And the corresponding rotor:
https://www.realoem.com/bmw/enUS/sho...diagId=34_0976
This probably is the best non M upgrade that could be done..but someone will have to try it out..Wish it was available state side!