Physical recoil applies it as an actual physical force, once that force is applied there is no other logic running to change the recoil any, there is no decay time or recovery time, I let the physics engine handle it based on the grip strength and the force that was imparted.
The non physical recoil is logical, not physical, so those parameters are used.
The equivalent of that with the physical recoil would be raising / lowering the imparted force applied per recoil instance, which would lower or raise the amount of recoil. Also could adjust the mass or grip strength to make it recover quicker too.