One thing with having monsters search for a hidden sniper is that you'll more easily be able to pull mobs to each other, like Githyanki patrol towards the Flaming Fist at Waukeen's Rest.
(I've heard of solo players doing just this, but as it is currently, it's tedious.)
I'm not sure if this would feel cheesy or smart tactical play? I suppose it'd be like barrels, up to us players to choose to use or not.
