I could have told you that the 12mm would rub in the rear for sure with the 275/35/19 with a mild drop. I have experience with running 10mm spacers with 265/35/19 ad08 on my zcp wheels in the rear and it has a very slight rub on huge deviations on the fwy when the suspension compresses completely.
For the fronts, I ran 255/35/19 ad08 + 10mm spacer with a 1.5 inch drop (kwv3) and it rubbed at 3/4 lock both left right. Its super hard to run aggressive tires on this car without rub on a stock alignment.
I ran ad08 255/35/19 F + 10 mm spacers and ad08 295/30/19 R + 0 spacers for about half a year and I got so sick of the rubbing I just ended up getting stock sized ad08's and I've been quite happy with the grip and performance.
Peanut Butter Chunky