I think that his approach is doomed to fail. There are a lot of tricky parts to flavors and multipackages and normalization. If you don't use the actual ports/packages framework code, you have to figure it out all over again by yourself.
and there are lots of gremlins. The official code is based off sqlports. See how many commits there were to that code... especially the tree-walker part and normalization part... that will give you an idea of everything that must be gotten precisely right to yield good results. (and btw, I initially wrote bogus code. I had a large debugging session with Robert Nagy until I got the normalization part correct!)