The issue is that on long range people could just spam their action button till you report that you spotted someone. At least from what I've heard people use it like that in arma.
An easy way to spot someone would be nice, but the above issue should not occur. The same with automatic voice commands when you see a grenade land next to you, you should not always shout grenade automatically, so people know where you are.
Personally how I think it would be best would be like, you press v1,6 which means report enemy sniper. Then a BIA alike mouse pointer appears and then you move it to the enemy location. And then you simply say enemy sniper at position blah blah. And then that sniper position gets marked on the hud and in 3d utilizing the hud on demand system.
But for stuff like a grenade landing next to someone you need to yell grenade fast without that voice comm thing revealing your position at all times (especially when no friendly is next to you).