Just a thought about the sub-package proposal:

It might be possible to do a simple implementation where builders are
required to install all the files, but we have several
PLIST-{bin,lib,includes} so when the package is registered are the
binary package is created, we create foo-{bin,lib,includes} with the
corresponding PLIST.  We just make sure the PLISTs don't overlap in
any way.  I haven't thought about how to deal with dependencies,
though.

	Just my two cents,

     -- Johnny C. Lam <lamj@stat.cmu.edu>
        Department of Statistics, Carnegie Mellon University
        http://www.stat.cmu.edu/~lamj/