Why do you think you would be losing traction when the inside rear wheel is off on a FF? That tire does very little, your grip will be on the outside wheels, more specifically the front outside wheel.
Do you have a floor jack at home? Take a picture of this scenario for me will you please...? At the rear of the car underneath should be a tow hook/jack point directly in the center...please jack the car up until the rear wheels are just barely off the ground...just enough to slight your a piece of cardboard under it then take a picture from the side...
BTW, if a FF car has it's inside rear wheel up i can almost bet you it's not sliding...it's gripping just fine
