Reference Points and G3 continuity

Control points of splines and ISDX curves cannot be used as a reference for other features. You can define datum points for the spline/curve to pass through that can be controlled directly. Have you considered this approach?

You can also import an .ibl file and use this for a curve through points approach.

Not quite sure how you are trying to reference the points.

If you are trying to go through the points with your curve, you can hold shift and select each point in order.  The ends can then be controlled using the tangent tab.  If you need to control the curve at each point you will need to make multiple curves from point to point.

In a previous life, I worked with airfoil shapes all the time, for turbine blades/stators. To represent the airfoil shape, a data file of points was used for each planar section of the foil. The critical thing about the files was the distribution of the points. The spacing of points was larger on the majority of the airfoil on the suction and pressure sides of the shape, and would get smaller as the points approached the leading or trailing edge of the shape. If I recall correctly, we used over 100 points each side (pressure/suction) of the airfoil.

Unfortunately, how those points were generated was very proprietary, and even if I had the mathematical techniques at hand to do so, I probably wouldn't be allowed to post them here. But, I'd imagine if you have a mathematical method of defining the points you are generating, you could perhaps generate points based on curvature at adjacent points? More points for more rapid change of curvature? I don't know. It's not an easy problem to solve, but there has to be some sort of "standardized" method used by people building windmills, yacht keels, etc.

I've had some complex curvature parts that I needed extendable surfaces for, and I have resorted to a .ibl file to get what I needed, but that was a lot of trial and error.