Stern design considerations

[PonoBill]

I don't know if forum members are familiar with Stand Up Paddlesurfing, but it's a relatively new discipline related to surfing. Development is headed off in two directions--better surfing hulls and better flatwater or open ocean racing hulls.

I'm interested in understanding what design choices go into a stern configuration. Most distance racing SUP boards (and paddleboards, surfskis and ocean kayaks) use a long tapered pintail for the stern. It seems to me that for the same length hull that a flat or shorter triangle shape (called a squash tail in surfing parlance) would enable the sides of the hull to be straighter, and might decrease overall drag because the flow separation would be abrupt rather than realized over the length of the convergence of the sides into a point.

Any input or direction of places to go for information would be greatly appreciated.