As a Wikisource editor I often export in ePub/PDF to check that the export is good when I am finishing to proofread a book.
Then I fix the issues I have spotted and download the book again.
The new WS export cache makes this workflow more difficult: I now have to go to ws-export.wmcloud.org, check each time the "no cache" option and then download instead of just clicking on the "download in ePub" link of the sidebar.
It would be nice to simplify this workflow.
What about an option in the new "Download" dialog on Wikisource that would allow to bypass the cache?
It should keep its state between downloads.
It might be meaningful to display it only to logged-in users that are more likely to be in an "editing" workflow than in a "reading" workflow.