Need simple way to migrate large number of documents from Appian-based application to non-Appian application

We need a simple way to migrate a large number of documents from our Appian-based APS application to a non-Appian application. To do so, we need a way to attach metadata to the physical files that reside on the application server, under accdocs.

We can obtain the following information regarding a document in Appian:

   Document Name: sf1449

   Document ID: 59834

   File Type: TXT

   Parent Folder: All Objects > APS Community > Contract Documents > Contract CORFD-21-C-0001 > Attachments

   Parent Knowledge Center: All Objects > APS Community > Contract Documents > Contract CORFD-21-C-0001

   Parent Knowledge Center ID: 59680

Using the Parent Knowledge Center ID, 59680, we can find the folder on the application server where the document is stored.

   Folder on Application Server: /app/APS/_admin/accdocs1/59680

By going to the application server and visually inspecting and/or downloading and inspecting the folder contents, we can obtain the full qualified filename of the Appian Document, including path:

   Full Filename on Application Server: /app/APS/_admin/accdocs1/59680/10023478.txt

However, there are well over 100,000 documents in our APS application and performing these steps on a file-by-file basis would be incredibly time-consuming. How can we go directly from the Appian Document to the Full Filename on the Application Server?

As an alternative, is there an easy way to download Knowledge Centers as zip files?  We are on Appian 18.2, and the Appian designer interface allows us to download the contents of as many as 25 KCs at a time.  However, due to the very large number of KCs in our application, this is not very efficient.