i tried it with the CH-67 Huron. the helicopter "drops" the cargo (cargo is on the ground) but the cargo is still connected to the helicopter on the ropes and the helicopter does not fly to the next waypoint.
i can shoot the ropes from the cargo off but it should work correctly.
i tried it with a car (suv) that works fine but not with the container (support) but i have not tried it yet with all objects.