Are you dot-checking the normals before you average them?  We can't be sure which way the normals of the candidate vertices will point.  The close vertices may be pointing in the wrong direction, and depending on the vertex locations they may be over-represented in the average, distorting it.  This averages out, for coordinate positions (but may also contribute to some of the inaccuracy seen in the closest vertices method).  For the normals, I'm not sure it would average out as desired.  We're determining one path with these, which will settle on the target tripoly.  It needs to be steered with care.  :lol:  I think it would be okay for convex surfaces, and less likely to be a problem when the mesh density is lower.  The trouble would show up in high-density, concave mesh regions, which is where I'm seeing it in Vicky 3, going uphill.

I should say "you", and not "we", but then it sounds like an accusation.   

===========================sigline======================================================

Cage can be an opinionated jerk who posts without thinking.  He apologizes for this.  He's honestly not trying to be a turkeyhead.

Cage had some freebies, compatible with Poser 11 and below.  His Python scripts were saved at archive.org, along with the rest of the Morphography site, where they were hosted.