Hi,
at https://git.devuan.org/farmatito/migration you can find
the latest and greatest Debian to Devuan migration script
supporting Bullseye to Chimaera conversion.

Supported DE’s:

   GNOME/GNOME FLASHBACK
    LXDE
    LXQT
    XFCE
    KDE
   MATE
   CINNAMON

also SERVER migration is possible but risky
if you are not sitting in the same room with the server.

This script is tested only in virtualbox as I don't have
machines to migrate right now.
Backwards compatibility for buster to beowulf should
work but is untested.

I hope there are some fearless testers!

Hints, improvements and critics are welcome.

Ciao,
Tito