Sorry Phillip, I'm closing this feature request because the benefits would likely be outweighed by the costs (maintenance, learning curve, module complexity, etc).  It was not the goal of the module to become a complete combinatorics toolkit; rather, the goal was to provide a set of practical tools for reasonably common needs (i.e. generating combinations of test case inputs).

You are invited to create a full-featured third-party combinatorics module and put it on PyPi. If the quality of the module is high, I will provide links to it from the itertools docs.  If the external module becomes popular (demonstrable user demand), I'll re-open this feature request for further discussion.