Quoted from Law:A-3 would likely be the easiest. Most bounces off of the lane rubber will just go back into the shooter lane.
Huh. My initial thought was that that diagram was right and that the easiest setting would be the one that keeps the ball out of there the most. But I think you're right now looking at it more. Especially with the '3' position being lower than the unmovable one.
Using factory defaults myself, but it's interesting to think about.