I dont care what your setups have done on FMU's, they are NOT tunable, bottom line! With a 12:1 FMU, there is no way to tune it, it simply increases fuel pressure by 12 psi per pound of boost the FMU sees. That means if your static fuel pressure is 42 psi or whatever you said it was earlier, and youre running 7 psi, your fuel pressure would be = 42 + (12x7) = 126 psi

The problem with FMU's is that they cause extremely inconsistent fuel curves, some spots might be extremely rich like you mentioned, while others might be extremely lean. And as Im sure youve noticed, this causes a jerky transition into boost. Ive run both an FMU and a standalone on my setup, and can tell you flat out, I will NEVER again use an FMU, no matter what the financial situation is, because of how easy it is to chip your ecu and run crome or uberdata. Pay an electronics shop a few bucks to chip your ecu for you, get PHiZ to send you a map for your setup, and buy some DSM 450cc injectors for under $50 and youve got yourself a solid fuel management system. That setup mentioned above has been proved time and time again to be reliable, safe, and make good power.