Unround parametric mouthpiece

This is a more or less experimental design which makes use of the fact that a 3D-printed mouthpiece for trumpet etc does not necessarily have to be round.
It has parameters to control the "unroundness" to create elliptical or squary shapes of the mouth end of it, while the instrument end is still round.
It uses Openscad and 2 libraries, both found on the OpenScad homepage (closepoints and polyround)..
The jpg shows and example Flugelhorn Mouthpiece with a mild squarish shape.
It would be great to hear from any experience and/or parameters!

I printed this on a ANET A8 with PLA @ 1.6mm walls and no infill.
I used the adaptive layer feature of cura and their new arachne engine which handles the relatively thin walls better.

Adhesion / support is part of the design but can easily removed.

Thanks to tdx00 for the suggestion to add a Z-shape, I have just updated the design to do so!