R.J. Gardner wrote an answer about Rossignol FKS 140 Ski Binding on August 6, 2014
Technically you aren't going to have the chance to go up a full shell size if your asking because you want to get bigger boots without changing the mounting position. The heel piece of the binding can me adjusted about 5mm forward or back like you mentioned. The sweet spot is right in the middle, but the binding will be fully functional even if adjusted with that forward pressure screw. The main issue is going to be that if you are sizing up a full shell size in a new boot then the larger shell will most likely be 10mm bigger so you would have to re-mount most likely. This is really going to depend on what boot you have them mounted for currently, and what boot your trying to adjust them for to give you a definite answer on if what you want to do will work or not. Feel free to chat in and ask for me, or go to my profile page, follow me, and reach out via email. You can also go into a local certified shop to have them look at both and re-mount them for you if needed for your new boot.