Hi Danny,

> How about automatically replacing the surface if planar?

That could be possible but it has some side effects like for example right now if you extrude a curve such that it generates the type of vertical surface you have there, if you want to edit the control points of it, it might be weird if you got a larger 4 point plane as the surface to edit rather than one with the control points of your original curve.

One of the ways that Extrude works currently is that the surface you get inherits the same control point structure as your generating curve, if these kinds of surfaces were replaced by 4 corner point planes that would not be the case anymore...

- Michael