I could have sworn that years ago there was a means to download stories from Patronuscharm for offline reading.
It could have been an online downloader like the defunct flagfic, of which the only one I know that still works is FicHub which doesn't support Patronus Charm.
It could have been a program like FanFictionDownloader, of which version 0.95 doesn't seem to support partonus charm.
It's NOT the calibre plugin FanFicFare, or support for Partonus was dropped at some point.

Am I remembering wrong, or is it a defunct program? I should boot up and check what's installed on my Windows 7 computer as it's probably been that long since I downloaded anything from PatronusCharm, if I ever did.

Anyways, what program/website was used to download from there?

 

No idea about Patronus Charm or a crawler for it, but if you're looking for offline reading you know there's a downloadable file of DLP's Library, right?

https://forums.darklordpotter.net/threads/dlp-library-archive-11-27-19-zip-updated.38988/