I tilt the motor a bit to try and avoid a solid impact and idle. If it starts to ride up on one, I shift to neutral and let nature takes its course.
I do similar but I tilt the motor up a bit more so the bottom of the skeg is about even with the bottom of the pad. Rarely will the prop ever contact a stump in this position. It takes a little practice but works well.
With your boat on the trailer tilt the motor so that if you pulled a straight edge off the bottom of the pad, the skeg would be about even with that line. Now get in the driver's seat and note the angle of the motor. In this position, you still have the power to reverse the engine and stop the boat if you begin to ride straight up high-center on a stump. If you get the motor too high, you lose most of the reverse thrust.