Chuckles
As always, your one thousand words paint a very clear picture indeed.
I notice you slashed OM/DME together which is really the essence of this debate I would have thought.
The OM alt check should be merely the confirmation of the comfort zone you should have got yourself into a lot earlier, perhaps as the coffee was coming through the door.
All those mental arithmetic commonsense checks one learns along the way are the circuit breakers designed to save your bacon. Just because a screen tells you one thing, it does not mean you put your thumb in your bum and your brain in neutral the rest of the way down the GS.