Quote - Sounds like it might be possible, but why would you want to do that, what's the objective?

In the past, I've tried body handle chains as a way of creating a poseable cape, which can be done in Blender.  I never got it to work in Poser.  I'm not trying to do anything like that at present.  When I mentioned actor chains, above, I was just including that as one of the various limitations of Poser's rigging system.

Quote - I'm not sure. A parent can be influenced by a number of children, so I'm guessing that a sibling can be influenced by a number of siblings. I'll check this out.

I was thinking more in terms of a sibling being able to deform multiple siblings.  I don't think there's a limit on how many actors could influence a given actor, but having the single actor influence several others seems like it might not work using otherActor.  Dunno. 

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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.