Probably a simplistic answer, but I thought the bend and twist JP's had the full effect within the inner mat sphere, gradually tapering off in the range between the inner and outer spheres. Perhaps, if this is true, you are asking about how the effect takes place in the range between the two zones? Sorry if I've missed the point. I'll step back now and wait for a more technical answer....

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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.