It's a bit more fundamental than that. Suspension isn't high OR low speed, there are just different ways suspension reacts when it's traveling at different speeds, and in fact completely different parts of the fork that contol the motion at low and high speeds.
They can tune the damping characteristics to whatever they/you choose. It just sounds like that they didn't get it right for you the first time around. Based on the fact that their bread and butter is sportbike suspension with half the travel of a GS, it's not all that suprising.