Found earlier and relevant questions on 22" and PSI:
Correct Tire Pressure
https://g05.bimmerpost.com/forums/sh....php?t=1668176
Thread above for 22", 38-39F/45R for 5 passengers. You can lower depending on your comfort or less than 5 passenger load.
For example, I'm running 33F/41R on 20" A/S. I wouldn't run 22" less than 36F/42R or equal pressures front and back.