I have jacked the rear using the differential case but always have a wood block to insulate from the metal jack pad.
I then place the metal jack pads on top of my jack stands and then support the weight on the jack stands at the jacking points on either side of the vehicle
These jack pads are also convenient for me in using the trolley jack at the pad locations when I need to jack up just one side of the vehicle quickly without having to dig out the factory jack from the vehicle.
Mike