Salute!
Well aware of that, PJ.
I use that altitude because it is my cabin altitude, and until I succumbed to lung damage built things, moved things, cut down/sectioned trees for firewood and easily ran up and down the river there to fish and, and.... That being said, we routinely have a few sea level folks experience no kidding "altitude sickness" verified by real doctors at nearby Woodland Park, which is about the same altitude - 8,000 ft advertised, but as low as 7,800. So old and infirm folks are advised to spend a quiet day or two there before heading up to Breckenridge, which is 9,000 ft and higher.
My point is a personal monitoring device is better than simple cabin pressure device. The histoxic problems are more complex, as it takes time to rid your blood of some chemicals or gases you absorbed. Think about how long we pre-breath to get rid of nitrogen for our chamber rides.
On the plus side, my concentrator dramatically increases my saturation without the slight positive pressure that some systems employ, especially the folks in the U-2 or WB-57. Many of us that flew some of the old interceptors breathed under slight pressure all the time to avoid the bends from rapid de-compress, and it was not all that bad after a mission or two to get used to it.
So point is simply descending below 10,000 feet may not be enough to treat hypoxic events.
Gums sends...