1Z Engine Control Unit Clone: Differences 028 906 021 XX

Hello,

We are currently finishing a Volkswagen Iltis with a 1Z TDI engine for a desert trip next year. The 1Z engine is from a 1996 Golf III and has a WFS2 system (which was an optional extra). To be able to react in case of an emergency, I would like to purchase a second set of WFS control units and engine control units. The question is: how can I make this as easy as possible? Ideally, both control units would be cloned, so I wouldn't have to reprogram everything on each control unit every time. The question is: can engine control units and WFS control units actually be cloned? Engine control units have EEPROMs, but I'm sure the coding for the specific WFS control unit being used and the reading coil is not stored there. Where would it be stored then? And with the WFS, I've only seen one microcontroller, which is not easy to copy... Does anyone have any ideas?

"I often find engine control units (ECUs) on eBay with the part number 028 906 021 [XX], where [XX] can be various letters. Does anyone happen to have a list that I can use to determine which vehicle the ECU was originally for, and what changes were made to other ECUs with different ending letters. Were internal circuit modifications made, or is this just a different software version? That would be very helpful to me."

Thank you & best regards,
Marc.