You are correct. Lower PSI on a drag racer will promote traction - BUT ONLY ON THE DRIVE WHEELS.
We drive FWD cars. So, we are in a bit of a dilemna. We have to fight the rolling resistance of the tires (at the front), but also find a compromise that allows for greater traction.
AX is not that dissimilar. The rear tires help to keep the car planted in corners and on the straights. By tweaking the tire pressures in the rear, you can affect cornering and rotation. A stiffer sidewall in the rear can translate to greater rotation and more lateral grip through sweeping turns. Conversely, lower the tire pressure too much and you create drag.
As I said before, a lot is dependent on your driving style. If you are a "point and shoot" kind of driver, then you may not want or like a lot of rotation from the rear. Will it make you faster? Depends on the course and your line.
Higher pressures mean more rotation. Will that make you faster as the rear hangs out? Depends on how comfortable you are with that scenario and how you adjust to bring the car straight.
That's why I say experiment and find what works for YOU,