For anyone else that finds this and, like me, has trouble figuring out why Paperless might not be copying over its meta data in the keywords, you may have to do the following:
- Make sure “Write Metadata” is checked in the Paperless “Files” preference tab
- Select all documents in Paperless and change one of the meta data fields, click out of the field, then change it back if desired - this just triggers Paperless to update the file
- This was the key that I was missing: Quit Paperless. This is when it updates all of its files. You may see a progress bar if there are a lot
- The meta data is now in the PDF files and dragging them to DT should preserve it