Salute!
Yeah, Wolf, could have new NATOPs or USAF numbers, but I flew with the 10,000/25,000 ft rule for about 4 years and we routinely came home from a long way or cruised on a x-country at 25,000 k..... our regulator garadually increased O2 percentage and then we got positive pressure above 20,000 or so, but very slight.
reason to get on the nose hoze early is for future problems....
I still like person sensors more than cockpit sensors to help you.
Gums sends...