Hallo!
Hans has said several times in the past that he has no interest at all to work on pd-packages separated like you sugest, so I believe, this would only apply for packages maintained somewhere/by someone else, like GridFlow.
No, as far as I remember Hans said several times that someone should just do the work ... (but maybe Hans knows best what Hans said ... ;)
So if anyone would try to split the build system into such packages any work would be highly appreciated !
LG Georg