Hi,
I'm afraid, I'm late to the discussion and I don't find the thread about
it in the archives. But I want to share me experience as a "user":
I'm in strong favor of putting the system-configuration used to build
the disk-image into the disk-image.
Yesterday I wanted to give the provided QEMU-image a try (I'm still
using guix on a foreign distro) and play with the system-config. Being a
"newbie" to GuixSD it would be a great starting-point for experiments.
But I did not find it? There seems to be no system-config.scm in /etc,
so I would have to start from scratch - which is not that encouraging :-(