I offer inventory feature from ACE mod. I wish to be able put primary weapons(i.e. Rifles, MGs) to second weapon slot(where RPG or LAW now). It's realistic way to carry to guns along with backpacks if you don't have RPG. Second gun should be visible on back of soldier like RPG, of course. I think that player shouldn't be able to customize weapon in this slot. Just carry. Maybe magazine presence for this weapon in current mag slot of second weapon slot like now.