I would think that the "focus fire on one person" would be mandatory for this type of machine. People in a mob usually wont do anything until someone takes some initiative. Lets say that one person is planning to do something dangerous (starts to throw a rock). So far, he is the only threat at the time. If you fire the weapon into the group of "bystanders" you would be breaching the code of ethics.
At this point in time you either need to have two separate weapons (one focused on incapacitating one threat and the other for crowd control) or one weapon with two types of fire (as aforementioned). It would be a lot more efficient to have one weapon do the job rather two.

I know this is not what you were saying Complich8, but your point raised a good issue. As of right now, we do not know the dimensions of the area affected. Does this weapon have the ability to focus in on a single target and/or the ability to broaden its attack area? That would be a very unique and a very important feature that i think they should include in this weapon. I'm sure this could be made possible by making the source dish-shaped and having a movable lens that would be able to broaden/close the area of attack according to our laws of lenses.
What would this do to the intensity of the heat blast though? I know if you do this with sunlight it would tremendously increase the intensity, but i guess you could have the motion of the lens function inversely with the intensity of the beam. That should solve the problem concerning that.