Well, one could apply SubD for smoothing during the render process. In fact, I believe some render engines do just that, due to some nice limit properties of SubD surfaces. But you're right, that doesn't necessarily mean that any smoothing applied during rendering can be interpreted as a subdivision process on the mesh level. In fact, I'm starting to suspect that the micropolygon smoothing in Reyes might work entirely different.

Anyway, still interested in getting some more info on the process, if someone comes along who has it.

-- I'm not mad at you, just Westphalian.