Its hard to explain in words but I will give it a try and confuse hell out of myself and you.
The me7.5 ecus in the AUM are load based what ever the requested load is for the ecu will do its best to produce it that why AUMs always make good power stock.
The engine torque is regulated via throttle position the ecu will make the power the best way it can taking in to account all the envirometal conditions, so you could have your foot hard to the floor but the throttle valve would only be open 80% when on boost, or in other words throttle valve position is not a driect relation to the pedel position.
So by allowing AUM car to run WOT when you foot is to the floor with the boost PIDs controlling the boost via the n75 duty cycle we can make the most of the boost to get some strong power at the top end.
We have been playing with these 4 maps for over the last 3 months to get it right and now its about 100% spot on I I can under stand the relation between all the map so I can make the power where we want, then you get Chris watching over me making sure every map is as smooth as it can be..

But saying that and getting this far with gen4 we have come up with another new aproach for the AUM mapping to flat line the boost PIDs / maps to work the same as you would with a electronic boost controller, so the boost will get straight to requested peak and hold there and using the load maps to control the power via the throttle valve.
I will be playing with this idea over the next few weeks. If I can find a victims car to play with..lol
Nick