Ok we are cross purposes here. The Mechanism of being spring loaded is what I thought you was wanting advise on.
The fact it's direct drive off the stepper shaft is because it's being used for plasma machine which doesn't require the same resolution and torque that router requires.

This is why you have seen other systems that use belts n pulleys. It's got nothing to do with Kickback. The belts/pulleys are applying ratio to increase resolution and torque.