From your description, it sounds like you don't want to eliminate the "hands at the sides and not touching any firearm" from SASS default and just want to override "the shooter shall stand upright" with your stage instructions. And that's ok.
However, some stage writers don't care if your hands are hovering over the gun, so they tell you that you can have your hands anywhere you want, but they don't want you to actually touch the gun. You can be a millimeter from it, just don't touch it. Some don't even care if you are touching it, either, and they will override that as well. Different strokes for different folks.
Ya, but will everybody else see it the same way? Or will some see the different wording and assume there is a difference in a prohibition between touching something and having something else in hand and argue about it for three pages on the wire?