I just did a bit of a test on this...
Set your aftertouch to Filter Cutoff... very high! (Or something *very* obvious and extreme!)
Then, test your aftertouch response. (Pro 3 has total shit on/off aftertouch response... - BUT!.. The 'better' Kurzweil "response" from my K2600 [controller keyboard] is only a *little* bit better!
-- [I CAN [VERY carefully] get a bit of a "middle" aftertouch-value here on the Kurzweil, but, really, not much. - So, maybe we need to yell at Fatar?]