Send me dump of ecu. I will try to make you immo off.

Unfortunately, I have no tool to read MSD87.1 😞

Just an update...car won't start with original 523i CAS4 with ISN copied from 528i CAS4

UPDATE no.2. Changed VIN in 528i CAS. Car starts OK, many fault codes are now coding related, but I also have now variant coding in 528i DME...strange cause it's already hard-coded in OL option and CAS4 is from the same car with the same power class.
Would VIN difference between DME and CAS affect power class? Food for thought.

I want to thank AUTOHEX_BMW, Findlaybaum and Tibibond for their interest and helping me pulling the ISN from both CAS4.