Here's what was sent up to Tom Burkland for DARKO.
All the aft-body is rounded over,combining tumblehome and edge radii as in Paul Jaray's original 1922 pumpkin seed.
Here's a rough 'thinking out loud' rendering.
An aerodynamic boat tail must have this rounding to perform to it's optimum,especially when truncated,as Morelli is telling us.