my (available on the mailing list but not integrated) patch for the library gives you a callback into just that point in the process where the library has parse

my (available on the mailing list but not integrated) patch for the library gives you a callback into just that point in the process where the library has parsed out what it can but hasn't filled in defaults yet, so you can insert the assumptions that make sense for your application and not have to rely on the default ones.