What are you running now with regards to the mbc? I take you're talking about the deviation error when you say there's less tolerance? How far have you managed to push yours Dave?
I had to go back and have a look at logs then. Actually, Stage 3 on HB9 is requesting 2400 so it's not a long way to the map sensor limit from there, obviously less than allowed deviation. My mbc is set for 1.5 bar of boost all the way to the red line.
The Mafs I've had from Euro have always been better packaged (protected) than the ones I've had from dealers.