and I know that is nothing new or something you dont know. I think a lot of it also has to do with how you launch the car as well. For me, the softest setting in the rear and a mid/low setting up front have always performed well for me - much better than making the rear stiff regardless of the setting up front. I'm not sure what kind of camber you are using, but I suspect your rear camber is probably too negative. This doesn't allow for maximum tirepatch and it only worsens when the rear squats. My rear camber is set to 0 degrees and under full squat it comes in a little to about -1.5 degrees due to the suspension geometry. They say the car has anti-squat design, but you can still make them squat and I have found it works to my advantage. I haven't put a set of good drag radials on my Z before but I'm looking to see ~1.5-1.6s 60' times here soon - making it squat the whole tracklength. =)
I think, perhaps, instead of giving advice on how exactly do to it as it has been before, encourage people to try new things and figure it out for themselves. Case and point: What you are suggesting vs. what I have found to work are in total contrast of each other.
