Basically:
Brake Coefficient determines how much engine braking you get. Higher values = more engine braking, and thus increased oversteer sliding when not on the throttle.
Dynamic Friction controls the way grip drops off when skidding. Higher values don't stop the "blocking" however.
You might also want to tone down the brake pressure, the friction of the brakes, or brake sizes.
A combination of all these changes should stop you from spinning off a cliff if you lift the throttle.