I am trying to create a Loft feature where both profiles and guides are segments in a 3D Sketch, but it does not work.  InsertLoftRefSurface2 works fine when I use curve features instead of sketch segments.  Moreover, I can create a Loft feature based on sketch segments in the GUI.

The one difference between GUI and API that I see is that when I select sketch segments in the GUI, SW pops up "Selection