Typical WGDC increase going from catless to catted

Hey all,

Went from a catless HKS flat flange DP to a (very used) catted Cobb DP a while back. As I've heard might happen, the car started underboosting 2nd and 3rd gear targets by 1-2 psi. Since I've got a spare motor almost together, have been reading Romraider forums and tuning guides for a long while and am interested in learning to tune, I corrected the underboost myself as a sort of first learning exercise.

Through an increase in WOT WGDC, a bit of reshaping of the boost contour, some small tweaks of P and +I gains to get the boost response to track the target nicely w/o overshoot or ringing, I've got it right where it used to be in 2nd and 3rd gear with the catless pipe. No knock at all so no timing adjustments made.

It took a 15-20% increase in WOT WGDC initial and max values to get it there. Wondering if those more experienced could comment whether a bump this size is typical going from catless to catted. Wondering if there's a chance I'm picking up some extra back-pressure from some blockage in the DP cat?