As much as I don't read all of these threads, and barely get on them out of interest....For that matter - I would be extremely leery of any tuner who doesn't want to work with other systems! They are just trying to sell you their system of choice! It takes a few hours of your effort to install things properly and tuck the wires away and to make it all look nice and stock. It takes some time to play with the software to "get it" and then after that it should not take more than a few hours on the dyno to get it running well.
You ma come back for a second session to fine-tune some things and you may have to play with it a bit next winter to get the cold-start dialed in.
There are many dyno-operators who will gladly work with you, once they know what buttons adds fuel in milliseconds and what reduces fueling - and conversely - how to advance timing or decrease it! Period. After that it is all basics of tuning, no matter what the system. I am available by phone here in the US and so are the guys in SA (on the same time-zone as your Euros!)
This bears repeating.
I've looked at various systems, all with their schemes on cacluating fuel. If someone is really familiar with EFI, they should be able to do any system, any time. If all they know is their system, and don't want to learn anything else- that's not good- as problems may not be solved in the right way, but in the convienent way. I know I prefer systems that don't use time for the injection map, but I can deal with them...
In the end, it is just fuel, air, and spark.
(on the funny side, our systems now are running in the 2.5 MB range... holy cow- so many sources of fuel, air, and spark do deal with.)