Seth Vidal (skvidal(a)fedoraproject.org) said:
Curiously enough you could make a fedora spin repodata now with
mergerepo and then modifyrepo to add the spin-specific comps and
provider-selection metadata all pointing back to 'everything' for the
actual packages.
Or (sick thought of the day) have a package that drops a unchanging
repo definition, comps file, preferred app, metadata all on the local
disk, to define defaults for that install.
Bill