I think the real issue here is that you need a centralized repository to store all this stuff. ASDF-INSTALL, is, IMO, broken, because it has too many dependencies on various systems. In particular, it depends on Cliki and all the various individual web sites that host each of the packages. Cliki serves as the master catalog, and then each package is served by whatever means the original creator of the package wants to use. If a site goes down or somebody gets lazy and lets their domain name expire, it breaks all the other ASDF-INSTALL packages that depend on a package that goes away.
IMO, what's needed is ultimately something like CPAN. The virtue of systems like CPAN is that once a module is uploaded, it remains available to everybody in whatever state it is in as long as required. The author can get lazy, go off-grid for months, or even die and the system continues to function as long as CPAN itself remains up and running.