I say it's worth it for you to pick up a spare ECM to play with.  If you have a working ECM w/APR tune I would NOT mess with it.  I've been monkeying around with doing this and have already cooked one ECM and one OBD cable.   ECU's are actually cheap, I used car-parts.com to search junkyards and bought one of mine for $175 and one for $125.   Read read read! it takes some time investment in the archive posts to learn about the process.  After three weeks of on and off work tonight I finally successfully read/wrote to the EEPROM of my spare ECM. (where the VIN/IMMO code etc is stored)

The ME7_95040 utility is just meant to read/write to the SPI EEPROM, it's NOT for flashing a entire system/engine file.  For that you need to use the NEFMOTO software, or Galleto cable etc etc.

Well if you have flashing experience than that's definitely a plus. I don't know anything about the encryption that APR (etc) uses.  but they're just trying to protect their hard work so you can't really blame them if they make it hard.   So what year Allroad did you flash? My 2004 Allroad has IMMO3 which has been a slight pain in the butt.   The ME7.1.1 ECU's seem to be alot more finicky than the earlier ME7.1 like in the S4 and APB Allroads.

To the best of my knowledge 01-03 Allroads are engine code APB w/ME7.1 and 04-05 Allroads are engine code BEL w/ME7.1.1. (2.7T only)  My car is a 04' and is labelled 4Z7907551S BENZIN ME7.1.1.  If you got a ME7.1.1 ECU to work in a 01' Allroad color me impressed!