I disagree with making 2x2 roosts but it depends on what breeds you have. I have a heavier dual purpose breed and they are clutzy. They are doing better with a 2x3 board set with the wide part flat. They fall off the roost less and when they roost they can completely cover all their toes. Whereas if they wrap the feet around the roost, then parts of their toes might be exposed, which could lead to frostbite.
They have the 2x4's upward, not sideways. The bird's feet can't latch around the 4" upward portion and they will have to stand on the roost rather than grasp it. When a normal chicken roosts (maybe not your big ones though, not sure of your specific breed), the tendons in the legs automatically compress creating that grip around the roost so they don't have to stay flexed while they are sleeping. If they can't get their feet around an edge- when they sit their feet will curl and they can't get a latch and will do what your birds are doing and fall off.
That wouldn't work here in New Jersey.
Why? What is different in NJ vs NC? Not being confrontational, I'm actually curious.