Is there any reason that a ~2017 STI rear Brembo caliper wouldn't interchange with a PP rear Brembo? We already know the bolt up to the car fine.
They both use the same Centric rebuild kit for a 40mm piston
https://centricparts.com/part-detail/14335031
They also both use the same DBA dual drilled rotor
https://www.counterspacegarage.com/dba-4000-brz-pp-rear
https://www.rallysportdirect.com/par...otor-pair-rear
This seems to indicate that they're the same offset and the same piston size so there would be no balance change or alignment issues.