Reduce your spool until there is no boost bounce and see what happens. The higher spool rate is making the ECU think its over boosting.
Alternatively you can run a resistor on the MAF to trick the voltage, not sure of where and how, but google will find it for you. Or the HPD air flow housing. Which is what I did many moons ago. Worked a treat, I wound my boost out past 30 psi and it still wouldn't hit limp mode. Prior to this, 16psi was the limit. on the knocker...