mary, I think you're interpreting them correctly.

My thought on the matter is this: Our cats are faster when it's just beginning to fly a hull because of a combination of maintaing the righting moment and reducing wetted surface area. The problem is that as we fly a hull, the mast and sails start to lean toward the water producing an increasing downward component to the power provided by the sails. The farther you heel the boat, the greater this downward component becomes. If you were to lean the mast to windward so that if you fly a hull the mast remains perpendicular to the water and you reduce wetted surface area how can this not be faster?

BTW...I'm pretty certain that the open 60 tris have windward tilting rigs.