Hull Design Software Based on NURBS

Correct, Nurbs were invented to represent conic SuRFACE lines. But a Nurbss does not NURBS can describe an arc on the SURFACE of a conic. but it does not define the Solid that is behind that arc. so when you go to 3D modeling with NURBS, you have to drag along a whole bunch of extra math to deal with the Solids and 3D aspects of the situation.

The reason they went away from Conics is that while some of the math is much simpler (clash detection, solids definitions) others bits are not - and were beyond the CPU power of those days to implement. But your cell phone now has more power than the dedicated CAD workstations of that era. so I think it may well be possible to go back to actually using actual 3D Cones to define the shapes being desired.

this gives you fidelity of surface with the clash and volume math all in one set of equations