@TomTom Does this work? I’m not doubting you, I am just very uninformed and confused.
I read the RhinoScript Fundamentals page on Nurbs Geometry and also this forum thread How to increase control points without changing shape? which deals with adding control points to a curve while maintaining degree and curve shape… What I gleaned from these two sources is that “inserting knots is the only method of increasing the number of control points without changing the shape of the curve in general”. So given a curve (or surface in one direction) of degree 3 and the minimum of 4 controls points to satisfy, I would have to add knots, which would in turn add control points, to my curve (surface) until I reach degree 5.
Using either InsertKnot or ChangeDegree, the position of existing control points move. It seems impossible to preserve the existing control point positions and curve/surface shape while increasing degree.