If the helicopter is not on fire, then I don't have too much fuel. They will fly over gross, but not without fuel.
Fuel dumping for fixed-wing aircraft is only used because they can take off with more fuel than they can land with, so if there is an emergency shortly after takeoff, they may need to dump fuel to get down to landing weight. In a helicopter, if it will take off, it can land, and I ain't dumping fuel no matter what.