That is what you want in some situations. However, in my situation it hurts more than if helps. Thanks for your input, but I have track times to prove that they hurt more than they help. You don't want rear lift and front lift with radials and a manual. If you never transfer any weight to the tires, how do you expect it to hook to its full potential?
I'm not suspension expert, but I'll give this a shot. I'm a drag race minded guy, so keep that in mind.
Ideally you don't want weight transfer or lift or drop. You want the car to go forward, any other motion is wasting time. In the real world that's going to be impossible to do.
So when the torque of the launch affects the car it wants to do a few things, rotate the rear (pinion goes up) and twist the mass of the car in direction the engine rotates. Again, all that wastes time since that energy is not being used to move the car forward.
Squat is when the car drops down in the rear over the rear tires, when this happens you are wasting energy that could be used to go forward. It also is an indication that your rear suspension is allowing the weight of the car to take up suspension travel. This does have the effect of putting more weight over the tires, but it's not the best way. As you travel forward the rear end is going to unload and rise and you may lose traction again since the weight transfer you relied upon is no longer there. The rear dropping drastically also effects front end geometry, that's not a big deal in drag racing, but I would think in turns it would be.
When the rear geometry is setup correctly, the twising of the rear uses the LCa's to push up on the chassis, forcing the rear towards the ground. If the tires hold traction the car will rise some. The front will lift as well affecting weight transfer, if you have enough traction and power you'll get the fronts off the ground. You can limit the rise of the of the car through the suspension, but on a street/strip car that will affect how the car rides. This configuration keeps pushing the rear toward the ground as long as you have power applied.
I hope that helps.