Ultimately its your call. With a 17psi spring and map 4 programmed to allow only up to 15psi, it's just going to close the throttle to try to compensate. The PID algorithms are setup for 13psi springs as well. You can make a 17psi spring work but its the wrong way to do things.

Anyway, map 2 has a 17psi target. Once fueling is working So you'll want to set FF to 0 and try logging map 2 to evaluate boost control. With FF at 0 PWM should stay around 0.