You can have the “initial” lsd setting increased, this will produce more understeer but a stronger effect on the car from the Acceleration and Braking Sensitivity settings.
Additionally you need to make the front Natural frequency and damping ratios stiffer on the front compared to the rear, this allows the rear to absorb a change in weight transfer and be less reactive, as well as a the stiffer front will give more grip to the front than the rear.
Remember oversteer is the rear having more grip than the front.