The reason you wouldnt want to run rubbers with an overdrive is tire diameter. Because rubbers are 99% of the time the same diameter.
With foams, you true a split between front and rear tire size. When running overdrive, the front wheels will rotate faster than the rear, so you tru the foams down to suit the rollout. With rubbers you cant do that, so the drive train will be trying to run the fronts faster than the rears, causing drive train stress and scrubbing the tires.