Steve,
Judging from your response, I think I did both of us a disservice by providing too many details from my stream of consciousness. Here's the distilled essence of what I intended to say:
In your requirements document you wrote, "Finally, this analysis suggests that there are relatively few differences between a DPD and a DPV server ... [T]he WG must decide if two distinct protocol formats, with different syntax are warranted, or if a single [one] is appropriate." You then went on to conclude that they were sufficiently similar to justify a single set of requirements.
Based on the way the discussions have gone, I'm questioning this conclusion. By separating the two, DPV could focus on simplicity and efficiency (to better serve highly constrained clients), while DPD focuses on completeness (to serve the needs of highly capable, but perhaps contextually constrained clients). DPV could consume DPD services, creating a complete solution to a wide range of problems.
It is this last paragraph that I'd like comment on. Without some sense of agreement at this conceptual level, it's fruitless to dig into details.