The Atomahawk draws about 15 milliamps, nothing to worry about there.
The HAWK draws more like 50-75 milliamps. Also not much.
But if you add those high brightness displays, I think it all begins to add up.
However, the MK2 efx boards pulls ALOT more than that. And the power regulator in the MK2 is the original.
So I've never seen any problems with the power regulator circuit and the HAWK, AtomaHawk, efx etc.
But I've never put those high brightness displays in there either. And I don't know how much they draw so better be careful and do the math.
Mike