Currently the way to create .3d files is to use Arbortext Editor with Styler, select File > Print Preview, then from the APP Print Preview window select File > Save APP File. When publishing with PE, the preview result is returned in a PDF Preview window instead of the APP Print Preview. This means that if users have Arbortext Editor and are using PE to publish, they are not able to generate an APP .3d file.
The recommended enhancement is to (1) enable the APP Print Preview window with Arbortext Editor + PE. What would be even better for more robust tool integrations would be (2) a File > Publish > APP .3d File menu option and (3) XML to APP.3d being a supported output type when making PE server requests.