> Trying to figure out what a compiler might do in the face of undefined behavior is generally not a worthwhile exercise.

That is exactly the point of my post! If you think I disagree with that statement, we seriously miscommunicated somewhere.

The parts you seem to be concerned about are those where I try to explain why the abstract machine is the way it is. Hardware and compiler concerns do come in at that point, and my feeling is just dogmatically giving an abstract machine won't help convince people of its usefulness.