21 M3 SR+ Flashing/Programming MCU odometer and immobilizer

[user id adam]

Hey all, So I am at the hopefully end of my rebuild on this car. It needed a new RDU due to a broken rear mount and non responsive driver inverter. I had an indy install the new rdu with inverter, reinstall software and now I have a dilemma. Contactors no longer close even through service mode and with toolbox though it did before. (CAR HAS NEVER DROVE FOR ME). I brought it to Tesla SC and they attempted to flash the immobilizer and odometer into the new rdu with no success. The car has never displayed mileage since I have had it and they found out there is no mileage in the MCU (which is what copies the info to the drive units). Without knowing what that mileage is or calculated rotations as tesla uses, they have no way to flash it unless they manually write it which they havent responded as to if they would be willing to yet. This is partially due to having a scratch on my lower battery plate 7mm deep and they want me to buy a new battery (not happening). I am told this department is called FTS. Also I have 2 main errors as follows

DI_a015_immobilizer - which popped up after rdu replacement and wont go away even if i hook up old one.
BMS_a144_Hvp_config_Mismatch - this came after me trying to backup and replace the HVC in the penthouse and failing somehow. Though contactors still closed with toolbox after HCV replacement but not after rdu replacement.

I am hoping someone may have light on how to flash the MCU and get rid of my immobilizer issue. I was told LOKI scan tool could do it but $5000 is a bit steep (just a bit) for me to swallow