Frank, from my looking at the 3.8L GM (same manufacturer) blower, I was thinking that you could add that into the MS equasion. With the extra outputs of the MS relay board, maybe actually controlling boost with the bypass valve for load conditions.
EG:Uphill grade of 5% load detected by RPM's & MAP sensor = "Somuchboostpressuredesired" controlled by a PWM air bleed solenoid (converted GM IAC) to allow butterfly partial deployment. Say needed boost was 2.5 LBS, butterfly would close a specific ammount to allow that much boost & then control the diaphragm through the IAC setup.... It was how GM used the setup, if I remember correctly.

Just to let you know, if you take a 95 Bonneville, it uses the same ECU part number wether it's supercharged, or not. The difference is that the SC car has a different MAP sensor mounted on the firewall & wiring harness.

I wonder if anyone has decoded the GM ECU to assist in your tuning?

Ed