We did step up the pod and added the 11 degree kick to the bottom plate. The laterals do follow the hull´s contour in order to maximize flotation. So its kind of a hybrid hull extension/square pod. I wonder how much of the lateral flowing water contributes to prop grip.
I have heard the 2" leg rise per 12" setback rule of thumb. However, since this is just a rule of thumb it has its defects. Particularly, there is no guideline as to how much rise the step shall have. Like you mention, this would not apply to a hull extension as the water that is exiting the transom will not rise any more than it did prior to the hull being extended.
The idea behind these pods was to maximize the flotation while at rest, the pods top plate rests flush with the water line. No purpose in adding structure where it will not contact the surface or displace water.
Do you have pods or a 1900?