yup. safer option would just be to get inline "Speed Defender"/fuel cut removers etc. At least they do only one thing and that's it.
all the Mines ECU's etc are just a chip with a slight remap of A/F ratios and a few Hex values changed to remove limiters or move them higher up.
Problem is, there is no way of knowing if its a factory remap (that takes a factory spec setup and tweaks the ratios to get more performance) or if its been custom mapped by its previous owner for a balls out system that was on its car.
for example:
My GTS4 runs a 2530, intercooler, exhaust etc, and I've got a remapped ECU using an EEPROM to let me run all day on about 14 P/sI. For all intents and purposes it looks and works like a factory ECU. Put it on a car running a standard setup and it'll cause troubles.
That said, I'd take a standard ECU with a remap that's custom tuned over shelling out for a Nistune... in an R32 anyway. Maybe use a Nistune to get the map right (as an EEPROM has to be removed, flashed, reinstalled, run, and repeated all over till it's just right, comapred to a Nistune which can be altered live).