Whilst going through the chm file doing some alteration / amendments. I found I'd made a slight cock-up with respect to the AddNode command. I wrote add node is world coordinates, This is wrong. At the time I was doing all testing on the world workplane, so it seemed correct. But recent testing has shown the actual command uses the objects workplane.
The coordinates for Adding a node go from the objects workplane origin. The world workplane origin is x = 0, y = 0. But the objects workplane origin could be anywhere, and may not even be where the object is located.
Anyway. I've done some alteration but I've no idea if it makes sense. Workplanes are not the easiest subject to try explain, especially when working on 2D in a 3D coordinate system. Much easier to leave 2D on the world workplane, or use selector 2D/3D depending mode.
Anyone interested. Please take a look and see if it makes sense or if you think I made it too complicated and it needs changing.