Real outtakes (unreleased song) would be probably not the best stuff otherwise Mark would have already issued them on a later album.
there are several examples in Mark's carreer with unreleased songs that I would have loved to be released, more than released ones !
He didn't always did the right choos, right ?..
Making movies, Real girl, Eastbound train (demo version) In my car... are songs I'd love to have in official releases
and Millionaire blues, Gravy train, My claim to fame, Small potatoes, Camerado, Let see you, Summer of love, Follow the ribbon, etc... should have been on standrad releases imho
so, what is "best" stuff in Mark's head is not always what WE are calling best stuff...