After building the neato Host versioning described in Functional Reactive Propellor this weekend, I was able to clean up secret-project's config file significantly It's feeling close to the final version now.

At this point, the disk image it builds is almost capable of installing the target system, and will try to do so when the user tells it to. But, choosing and partitioning of the target system disk is not implemented yet, so it installs to a chroot which will fail due to lack of disk space there. So, I have not actually tested it yet.