Today I attached an adapter inline of the compressor signal lines that feed into the N75 valve.  The adapter has a fitting for a line that will allow me to record on the Innovate LMA-3 AuxBox the boost pressure in the compressor housings.

This will give me an idea of the compressor outlet pressure, rather than just manifold pressure, which is lowered by the pressure losses between the turbo outlet and throttle body, primarily by the intercoolers.