Tried the script. The Poser menu stuff doesn't work. Commented them out and just called the export and import on their own. They work. The wx dialogs work. I had to change a single thing (python3 map returns map object; wrapped in in a list) Exported fine (Poser12 on MacOS Mojave), imported in Blender (2.91.2). Sculpted. Exported that out, imported, named the morph and it worked fine.

Sweet thanks. I'll sort the Poser menu.