The issue I have had with Spot lock on my PDV2/I-Pilot is once you drift off, it starts at low speed trying to get you back. Then it speeds up until you get back to the spot. Problem is, sometimes it is going so fast, you overshoot the spot and the motor spins to get you back. This will twist the cables if not watching.
Same here. Also helps to point the boat into the wind. Pointing the boat downwind is when it tends to overshoot.