I can understand your frustration with the Speed Genie on the GT-11, but I must say that for the GT-31, they really have it dialled in. Once you are on the water, there is no need to press a single button the whole time.
I wonder if an impassioned letter to Locosystech might get them to make one more release of firmware for the GT-11? Of course, they'd like to sell a whole lot more GT-11's, but maybe they'd come around to bolster the goodwill of the windsurfing community?