I've finished polishing spline related tools in NaroCAD to be more complete and easier to use.
So you will have three spline types under NaroCAD and they will work a bit better than in the past.
Some fixes may be still needed but at large Spline related tools are nice to work with and you may enjoy using them (in next releases). OpenCascade 2D layers do not work concomitantly (or I've misunderstood how they work) but I've rewrite to make possible to write multiple texts so when you will use Spline you will see coordinates)
Note: cause of internal changes, if you was using in the past Spline Path tool, I do recommend you to work with nighties, because this functionality is rewritten in a non compatible way. Also the old code was making to add features on it (like a proper editing code) very hard, so will be unlikely to get fixes will be in that area.
So take a look:
Mistake: cubic splines are defined by 4 points.