"Every item doesn't have to work with both programs.  Just make it clear in the product description."

Precisly so.

Bejaymac is talking about what you as a user would need to do to convert a Poser Dawn piece of cloth to Daz. This is similar to try to put a Boeing 777 into a matchbox. The best way to do it is simply to export it as an obj and do all the rigging in Daz anew. Better to leave that to the content-creators. The way it was before, that V4 content worked out of the box in both programs is never coming back.