DayZ Mod and it's predecessors (ArmA, Flashpoint) had a really nice feature when you could look at the compas by simply holding G, without need to change item in your hands. Why not to return it in SA?
With further development of the game, it could be related to some other inventions. Like, it could be not a simple image of compass on the screen, but instead the character would hold a compass in left hand and the current item in right hand (with animation blending system, it'd be something like the gestures). Or maybe this feature would be allowed only if you have your compass in a "nearest pocket", in a jacket or a vest.