I just adjusted mine and initially had the same problem as you. Trick is to only back out the screws half way. Then hold the boot between your legs, toe down. With the screw driver still in the bottom screw, push down on the screw driver while with your other hand push the upper cuff forward. You shoud feel it slide and I noticed the plate is now as low as it will go on the boot toward the +. It's a very small move but I did feel it go. Don't bother trying to sight the indicator line at the middle of the plate. If I were to look at that I wouldn't be able to tell if it is still in the neutral position or not. Can only really tell because the plate is up against the bottom recess now and there's more space at the top. Good luck.
