Cupcar

Removing the rubber also allows the sub-frame to stiffly triangulate between the chassis side rails of the engine compartment and the chassis floor ahead of the rear wheels. Maybe this is what is meant?

This is a nice drawing of anti-squat geometries:

Bill Verburg

The best explanation I found is here at Race Car Tuning

Cupcar

One thing to note about their explanation is that they don't mention that if the convergence point of the virtual center is at the CG level that is 100% anti-squat where the two forces are neutralized.

If the convergence is at ground level that is 0% anti-squat where only the rear springs resist squat.

If the convergence point is above the CG level then there is front end lifting - which is what drag racers want because front wheels off ground = all weight on rear wheels.

If the convergence point is below ground level then there would be front end weight transfer driven by rear wheel torque.

Bill Verburg

Also interesting to not is the relation ship between the tilt kit and adjusting the KT arm.
when the KT arm is lengthened both caster and camber decrease, rear caster spec for RSR was 3° or as close to tilting the forward part of the rear suspension down as it gets.