I'm not grasping why the maximum torque is only at 2300 rpm with a boost level of 8.5 psi.

Something is not right. There is no reason that this engine can't produce peak torque at 2800 rpm. Randy and others have dyno runs that confirm this.

This engine would have significantly more than 107hp if the torque peak could be shifted to the right.

Are you positive that the cam timing and IP timing are correct? Is the lift on the cam to spec?

Something needs adjustment.