Hello ! This will be my first post here. I read through the whole thread and found it very interesting, but it made me think about a few things:
1- Since the PS3 has a system structure pretty similar to the PSP, it possibly has a structure similar to what in the PSP is called "ID Storage"... Devs here refer to this structure as "Keyvault", right ?
What if this said "Keyvault" or "IDStorage" has a kind of version information which tells the HV (HyperVisor) what features it has to allow or deny ? I am aware that retail units (and possibly dev units too) have their bluetooth dongle, wifi board and bluray drives bound to their motherboard. Swap them around and they will not work on another PS3 system. I believe that a mark that set a system into DEV unit will be buried deep inside the "Keyvault" or "IDStorage" section of the flash, far from reach.
2- By what I understood, this swap method causes the PS3 to load the executable binaries from one UPDATE.PUP file (retail) and as the user swap the hard disk, the data section from UPDATE.PUP on the other hard disk will be read and written to the PS3.
This could cause several files from the DEV PUP file to be not installed as it will be still using the executable program from the retail PUP to flash the DEV pup data section on the PS3 flash.
I still believe it doesn't work because the DEV unit has a flag set on it's "Keyvault"