To clarify further, what I've personally seen trying to get IKM0S on 335is with its original MSD81, IKM0S full writes successfully and shows "IKM0S" under HW, but the current ZB defaults to my factory 335is ZB with it. I've assumed that this is because 1M ZB is not in the 335 chassis/sw chain so it defaults to original ZB as a fail safe. Address blocks used don't match rom = fail.
1M ZB I've been testing with is 8619150 (N America 1M).
When there's a 135 ZB as original/DME is originally from a 135, it DOES recognize the 1M ZB correctly as current software after flashing and works. Pete's originally a 135 DME in a 335 after Euro IKM0S flash (8619148). 135 ZB original->IKM0S flashed->MHD stage 0 flashed:
1M ZB I've been testing with is 8619150 (N America 1M).
When there's a 135 ZB as original/DME is originally from a 135, it DOES recognize the 1M ZB correctly as current software after flashing and works. Pete's originally a 135 DME in a 335 after Euro IKM0S flash (8619148). 135 ZB original->IKM0S flashed->MHD stage 0 flashed: