As has been alluded to, there is only one spot on the reservation/ticket for a FF# to go in. Benefits originate from and crediting goes to whatever FF# is in that spot. Even though you might have the FlyingBlue on your DL profile, the ticket & reservation is separate system from the overall DL profile, and all the ancillary things you might be able to list don't carry into the actual reservation. Think of your profile as being like an address book, when you make the reservation it will prepopulate certain fields based on your profile (traveller info, KTNs, FF#, etc), but once the reservation is made its not looking back at your profile for the information. It's looking at whatever was written to the reservation.