Buying a MS3ProPNP vs building MS3 V3.0 with Nippon Denso 122 Pin
 

I'm trying to figure out if there are any functional differences between buying a MM0105 MS3Pro versus building my own MS3 and then making an adapter using a nippon 122 pin connector or DIYBOB N122. I'd like to be able to load up the same tune used for the PNP unit and have it work without any changes. I couldn't find any photos of the MS3Pro PNP with the case off to see if the circuitboard is the same, or if it is a custom board for this lineup.
My job is to prototype, design, and test PCB's so skill wise this is not out of my reach! I couldn't find a thread about this yet, but if there is please let me know!

The PNP is definitely a different PCB. SMD vs thru hole as just one example, as well as all the input buffers, and protection circuitry they added that you would have to build from scratch. The daughter board determines the feature set, and the daughter boards as far as I know are the same. Maybe not identical PCBs, but same "chipset". So if you were to build all the circuitry al la PNP, I dont see why theyd functionally be the same ECU. You may also want to check the firmwares as i/o may conflict when loading your PNP tune to the "built MS3".