I would like to respectfully disagree with your characterization of the ice bulge on Central Gully. While it is true that there are times when the ice is indeed minimal or nonexistent, as you describe, I've seen it where there were actually several full pitches of ice. Also, while I agree that competent mountaineers can do it with just a single mountaineering axe and nontechnical crampons in average conditions, I would still recommend a second ice tool and at least several ice screws to a party attempting it as a first Huntington gully climb.
In summary, I would propose the following alternative description of the ice bulge: "The amount of ice can vary from none to a few meters to a full pitch or more, depending on snow amounts and other factors. In any case, the maximum difficulty of the ice is around WI2."