It's not a CO mainline rule, nor is it an FAA rule. Don't know about any other airline policy though. If anyone wants to prove me wrong, please cite page and paragraph.

In reality, someone who sits in the exit row should be able to fit through the hole, but determining that criteria would be difficult to say the least. It also leads to a can of worms in that, an oversized person could be sitting one row away from the over wing exit therefore causing the same bottleneck as they attempt to get through the portal.

We would have to relegate large people to sit in rows near the full size exits and direct them to only head for the exit they will fit through. Ain't gonna happen.

As far as the dangling extension theorem, that isn't going to slow anyone down---not one iota.