Wow! I returned to the DIS this morning to see if anyone has replied to my question (I was the originator of this thread), and imagine my surprise to see how it's sparked this conversation! Thanks to those of you who replied.
Now, let me add my two cents' worth to the other aspect of this conversation--the "dessert only" controversy. When I made the PS at Blue Bayou, I did tell the CM that I planned on having only dessert there, and he didn't say anything negative in response. Instead, he merely replied, "Okay. What time would you like?" I made the PS for the absolute last seating of the night (9:50 p.m.) for two reasons: 1.) I figured that if we tried to eat such large desserts right after dinner, we'd end up ill. 2.) I assumed that most people don't prefer to eat dinner so late, so taking up a table for dessert only at such a late hour would probably not be thought inconsiderate--or, at least, not AS inconsiderate as occupying a table at a prime dining hour, such as 7:30. While I don't see having dessert only as being inconsiderate to the restaurant (after all, my view is that they're making money and making guests happy--and isn't that the point of Disney to begin with?), I suppose it's possible that the restaurant workers could see it that way. Hence, the late reservations.
Therefore, if you want to try the "dessert only" approach to BB, then perhaps, like me, doing so at a late hour will make you feel a bit more relaxed about doing that? I don't know...just an idea.