Rebinding key combinations triggers key presses for single bound actions as well.

If you bind Zero Up to CTRL+Mouse Wheel Up and you have Mouse Wheel Up bound to optics mode switch, then every time you use Zero Up game triggers Optics mode switch as well which should never happen.

An idea: You have robust keybind configuration implemented to Arma 3, allow players to take advantage of that in DayZ as well and don't invent the wheel again as it did not really work.