odf posted at 5:07 PM Thu, 3 February 2022 - #4434348

... are there any posing systems for Poser figures that use ERC in order to move several body parts with a single dial? 

You mean master dials, something like arms up-down in the body actor of default LaFemme? Click the small triangle in the top-right of the parameters window and select 'create new master parameter'. You then enter the definition  and 'learn' process.

It may take a little exercise at first.