Why do the arms need any clearance at all? Why not just have them in contact with the boot toe?
1. Make sure you can barely slip a piece of paper between your boot toe and the binding plate. Used to be a credit card,,but more tech's I trust and interact with say..a piece of paper. You MUST check this periodically as this screw and the side screw back off...again, DEPENDING ON HOW HARD YOU SKI.
2. Make sure you, (while in the ski/boot) cannot wiggle the arms more than maybe a MM WHILE standing on the ski with your weight.
Hope this helps..have many pairs..always get this same advice from experienced techs I trust.