From a FT standpoint, the idea of being DBed for declining to sit in an exit row (POS-related or not) seems fascinating. Such a DB implies that not a single passenger (other than those already in an exit row) on a completely full flight is "willing an able to help the crew perform those functions in an emergency."

I personally don't see how it could be anything other than an IDB. The CoC does not require me to meet exit row requirements (15+ years old, speak/understand English, able to lift 40+ pounds, not traveling w/ infant, etc.), so I don't see how the Coc could require you to perform exit-row functions.

Of course, I also believe that a POS-related situation that cannot be resolved should result in an IDB.

To make it more interesting, what happens if you decline exit row duties, nobody else will volunteer, and the only empty seat on the plane is in F?