Unless you are running geared reduction or high reduction belt drives, i.e. an unusual setup, the steppers do not have the power to do too much damage if they run away or you jog into the end stop.
There's a bit more to it then that. You have to consider inertia. Think of a battering ram. It's not the speed it's moving at, but the weight that's moving. The moving mass has far more power than the stepper motors.
If you jog an axis up against the stops, and then jog into the stops, the force is only what the motors can deliver. Now run into it at high speed, and the force is much higher.
Sort of like placing a brick on a glass table, vs dropping it on the glass table from 10 ft up. Big difference.