Geez, it wasn't that cryptic. Since the long-stoker aero frame is out of the ordinary, if neither the manufacturer nor the customer initiates that the frame is to be different, the stock frame will likely be produced. There is inertia behind the stock frames.
So, we can't conclude from the use of stock frames by dedicated racers, be they track or triathlon, etc., that the stock frame is aerodynamically ideal. It might just be all that is likely to be produced.
I don't know if the Calfee that Cowie uses is any longer than usual. The obvious thing for a male stoker would be to order a large/large.
When I was visiting the Calfee factory in May, I took some pictures of the frame as it was being shipped out. Can we tell anything from the numbers?