in a very simple explaination

boost=torque so running a lower compression so you may run more boost will normally give you access to more torque, assuming that the ecu isnt advanced enough to allow high boost with high comp of course.

in your case, running a supercharger will give you more torque than a standard st170 and normally are designed for running low levels of boost anyway, so i would stick with a decent amount of compression.

if you were running a turbo and wanting 15psi+ then my advice would be to go lower comp