First of all, MED9 immo-off is done only in eeprom, so no need to read flash.
(I have never seen MED9 immo-off solution in flash, but please show me if it exists also.)
But writing MED9 eeprom (changing immo-off to immo-on) does require you to open the ECU. I have not seen a solution by OBD only.
Secondly, just read immo data from red cluster, have it convert to white cluster format and write it.
Then add some new transponders, and that's it.
You can leave ECU immo-off if you like.
Rgs H2Deetoo
I'm stuck with "Immobilizer active" after E2P immo off. Transponder chip is faulty too, but it currently starts and drives.