Skip running the PhysX simulation step if not required by Rigidbodies for 5.3.4

Hello, unity 5.4 beta10+ have a new physx;

"Physics: Skip running the PhysX simulation step if not required by Rigidbodies or WheelColliders."

how can i make this for Unity 5.3.4 ? I cant use betas cause lot of bugs and my project can not work properly.