What would be the best way to do such?

What I am looking for is creating kind of bell for a trumpet but should have irregular shape.
It's like using 2 polylines within a plane to define outer/inner shape and then extruding it but also giving the next level a different polyline.
It's like morphing a star into a circle like loft but with more levels and changing diameter and extrude along a line.
if this is complicated is it better to create .stl like with Python code combining vertexes to faces and importing that or can cadquery turn points into faces as well ?