I dont think that would be possible. The way the user groups are set up there is no way to give just certain permissions like that. It would end up creating a whole new user group. If it was even possible. Which it should be.
But then comes in teh process of selecting who would get that kind of power and who wouldnt. Cause while it can be used for good it could also be used to temp ban anyone that a person doesnt like ot has a arguement with as well.
We have a decent system. If there is spam that stays on for a while it is usually late at night when most of us US Mods are sleeping. We get it first thing in the morning.
The report feature would be better than PM anyways cause you might PM a Mod that isnt on or wont be on for a while.
It has potential but there are just as many downs as there are ups.