I am having a very similar problem, except occasionally after letting off the throttle it starts stumbling really bad and takes a bit to recover as if the MAF is not working properly.
But like your problem, if I stay on the throttle after hesistation it kicks really hard and often spins tires afterwards.
I am using a Techtom MDM-100 to monitor, and it shows that timing is not being pulled and that it is not leaning out. I checked plugs more than once and they are fine and gapped properly. I am only boosting 10 psi MAX.
I am also now running a z32 MAF along with Apex'i S-AFC to try and fix the problem but that is not changing anything.
Very frustrated and do not know where to look next.