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would be nice to delete unused materials from poser interface.  (currently doing this step in cr2editor)

I think you can do this already, if I am understanding you. On the right you can click on "Remove Detatched Nodes" and that will strip them out. You can also shift-click on it and it will do it for the whole figure. Now, if you are talking actual materials that get loaded in by accident when you click the wrong mat pose then that is something different.