Hi,
Some time ago, I created infrastructure to be used by ASDF to compile an ASD definition file's resulting FASLs into a single artifact. Things like #.(read-some-file) in the ASD definition will work as well. If there are load-time or runtime forms referring to the original source tree, they won't, because the link to the source tree gets severed.
Unfortunately, I can't remember the name of the ASDF transform I implemented this for. What I do remember is that the resulting fasl can be loaded with a simple LOAD command, so ASDF won't be needed in the resulting image.