Joe, check out the following video. I'm using linked pedal, the HST sensitivity is set halfway (straight up and down on the knob). I'm in medium range using 4WD. I'm opening my grapple just as I approach the fire and using momentum to "throw" my load into the fire as I transition from forward to back (cf. 0:50-0:60 minute mark in video for the first "toss"). You can see how fast my transitions are by also noting the engine rpm. You should have the same performance, and it can become more abrupt by dialing back the sensitivity knob.
All to say, play with the settings, but maybe something is out of adjustment that the dealer can sort out like you're thinking.
Wow, even I've never 'thrown' stuff in the fire yet with my Deere! I have 'dumped' stuff on..... Anyway, no, I am not getting that type of responsiveness, only immediately after the CAL light comes on and I have to hit it does it respond quickly. So, I've emailed the dealer to see about getting it looked at. Thanks.