Inputbox Fig writes a point list to FigO
Inputbox Grid writes a index list to Grid
Grid holds a list of index numbers of the points from FigO that belong to a spline curve.
There a 10 Sliders to manipulate the transformation point lists FigO->FigDT and spline lists FigOShape -> FigDTShape
Dealing with the transformation sliders always reaches the point where the spline lists disappear - no undo possible.
Does it make sense to save a file with disappeared spline-list FigDTShape for debugging for you? See attached file if it is interesting to you...