Said question is essentially the topic of their disagreement on OB late last year, is it not? I recall that discussion reaching no satisfactory conclusion. My impression from that was of a great deal of talking past one another, not so much a matter of of approach to the question as subtly differing implicit assumptions.

Would the meta-topic be likely to shed more light on the subject, or would it result in the same stalemate?

I suspect there are more interesting and fruitful topics that the two could discuss.