This doesn't use Parazyd's Devuan image, this bootstraps a Devuan system from scratch, similar to what my DebiaN900 scripts do after changing the repository URL to Devuan's. I am planning an update to make Devuan and mainline Linux the default.

This guide seems to have a few redundant steps. Emdebian was discontinued several years ago and cross compilation is possible using standard Debian, Devuan, Ubuntu, etc. There's no need to pin systemd-sysv as it's not available in Devuan. It's probably not a good idea to pin udev. As far as I'm aware, Devuan Jessie uses udev and will do so until the vdev replacement is ready.