I discovered a wrinkle (!) during my last project.  If you do a dynamics run and then save, Poser saves the settings.  However, it does so by saving the cloth groups within an embedded object.  If I tried to change the reference to an external object Poser would crash quite thoroughly and instantly the moment a cloth simulation was attempted.

So...you can set up a cloth object that is already "preset" with the correct groups and cloth settings, but it can not conform to current Marketplace standards for external object files.

Still, more experimentation on this might be useful.