Boxter non-s calipers and 28mm thick rotor?
 

Boxter non-s caliper uses originally 24mm thick rotors, but max width between pads is 27mm.

Would it be acceptable idea to use 28mm thick rotors by taking 1-1,5mm out of pad thickness?

EDIT: decided to try these boxster calipers rear with stock 944 turbo rotor and bought 966 calipers to front with wilwood 330x28 rotor.