In case of an emergency descent even more important than telling them that you do that is squawking 7700.
Nice theoretical idea, if possible. Rapid depressurisation, we are told, can cause severe misting and low vis. Not to mention the plastic face masks. If the reason is other than that it shud be no problem. That is alerting ground based agencies: I still think TA Only is a huge priority for our end of the procedure, but appears far to low down the checklist for my comfort, and well educated professionals should be able to find that knob in the dark. IMHO it was one of the first things I did from memory; even though I was told it was wrong as it was not a 'recall' item. Oh dear.