Yes, subdirectories would make this the PERFECT directory lister! I'd be happy to shoot a donation your way if this were to get implemented... or possibly even just for trying!
We have over 3,000 files (many years' worth of PDF's) spread throughout almost 400 folders/subfolders (like I said, MANY years' worth split into yearly subfolders). So while File Away is excellent, for our situation we'd still need to create almost 400 pages - one for each folder/subfolder - and then list the contents of each one.
Rupak's solution looks like a start, in that you can list PAGES as "folders" inside File Away. But from his description on his page, it sounds like you still need to create a page per folder and fake its appearance as a folder; those child pages still need to be made. If there's ANY way around this, we'd gladly pay for it!
(EDIT: I just saw your post from a few weeks ago... thanks for trying!)