Quick update on this. Blow through MAF setup is still working great.
But how I originally planned on dealing with the MAP sensor didn't work. I ended up leaving the DTEC MAP sensor alone. Bought a new TurboXS MAP sensor and cut the wires going into the UTEC from the stock MAP sensor and wired in the new TXS one. Then I made a jumper wire from the stock MAP sensor, around the UTEC and to the ECU. So the UTEC now get's a 4.5bar map sensor and the ECU gets the stock map sensor and everyone is happy.
To power the TurboXS MAP sensor, you need to splice into the stock MAP sensor's power wire as they both run on 5V, not 12V. Then just ground the TurboXS MAP sensor's ground wire to the chassis.