When I downloaded Debian testing or stable releases, I usually downloaded the .jigdo and .template files, and let jigdo-lite fill them up from the nearest Debian mirror ftp site.
Could we do this for Devuan as well? Then we could construct an installation DVD .iso from a .jigdo and .template file filled with only the Devuan-specific packages, and download the other 99% from the Debian mirror nearest to our respective countries. And when there are only few packages updated between release candidates, this minimizes the bandwidth to keep the release candidate .iso s updated.
I'm referring to a site layout like here: http://cdimage.debian.org/cdimage/weekly-builds/amd64/jigdo-dvd/