BMW cas3++ ISTAP key programming

Hey,
 
Do i need to downgrade CAS3++ ISTAP for new key programming if i have a working key just programming a new spare one or not?
I've seen you need to do it when all keys are lost but havent seen any confirmation whether you need to when you have a working key

Yes, downgrade required even to add key. I recommend removing CAS and reading eeprom to add key by eeprom. Much less risk and you'll have a backup incase they ever need another key.

No. You do not need to downgrade.
Vvdi2 can get isn with working key, or ecu isn.
Iff you read mcu inside cas.