There is a bypass valve just before the throttle intake after the intercooler which deals with boost level tweaking and routes excess boost situations (such as throttle closed) back through the intake.
You would need to remove this bypass valve, block the 2nd feed into the supercharger (or use it as an extra intake...), and add a dump valve. Not sure if there needs to be an understanding on how the bypass operates and when as I suspect it could cause a reduction in boost pressure as and when desired.
Unless you are going to start tuning it, such as changing the pulleys (I do believe I worked out there is some headroom on the rpm of the supercharger so it could be done), I don't see any other benefit other than having the car "sneeze" every time you change gear! But then you have the ECU to contend with, its quite a complex engine in terms of how it operates.. such as miller cycle running.