The Laplace method I adapted basically moves clockwise around the tri (or poly) and moves each vertex toward the clockwise neighbor vertex.  This approach has the problem with concave polys (apparently) and I've also noted that it has trouble with poles.  Try running it on a morph created on the Poser ball prop.  The pole ends of the ball seem to move toward +z or -z in my tests.  The averaging handles this aspect much better.

To understand his code, I kind of cheated.  I searched all the files for variable and function names and created a new document which contained only the pertinent code.  The vector math functions and a couple of those single letter functions were tricky to figure out.  It was made easier by the fact that his Z coordinates have more straightforward coding, which can also be applied to the X and Y.  It you glance at his volume- and edge-preserving code, however, you'll see a huge, long function which looks quite intimidating....

Okay.  I have multi-region selections.  Moving on to exclusions....

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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.