Ability to see the sweet spot as an AT gunner. This can be an upgrade. The AT gunner can gain the knowlege of where its best to aim.
we have aim indicator against tanks for good reason, most Enlisted players are too retarded to destroy a tank with even the green indicating pen so locking the feature behind perks would be devastating to those idiots.
You can learn about the tanks yourself by viewing their insides in the menu. It was one of the most effective things I have done in this game, as knowing the weakest spots I stopped dropping the tnt above the engine or turret and just started placing it on the ammo side and run to another for a cover
I dont even run for cover these days, I just run to the other side of the tank and use it as cover from my own explosive.
By saying “run to another” I meant another side of a tank, so yea I do exactly that, its the most effective way