Thanks. This seems it was prepared before the February BOF and is out of date. Even so, it is a pretty solid read for someone interested in an overview of current 3D printing models. Unfortunately, it also makes it clear that the white paper currently only supports FDM (fused deposition modeling) based processes, while stating intent to expand to broader scope.
Note the "copyright (C) 2015 Apple Inc" part (makes some sense given that Apple owns CUPS)