This is technical so please allow it...
Sleep disorder "experts" are not all alike. Some remind me of paint-by-the-numbers robots that work purely by rote and cast intelligence aside. Lower mask pressure for exhalation is critical for some people including me. The idiots that I had to deal with did not understand the capabilities of machines. My first unit was a CPAP and the results were a disaster. The second machine was a Bi-PAP. Me not they had to adjust the settings for optimum performance. One setting in particular senses the presence of breath intake. It is adjustable. I reset it to it's most sensitive setting and whammo my AHI dumped from 15 down to 1. The sleep study doctor threw a fit. I called him a quack in front of a dozen waiting patients and walked out. CSA? A person could say so. When hospitalized and drifting off to sleep came yelling "BREATHE! BREATHE! From the nurse's station. My sleep study doctor was a graduate of the university of Islamabad.
THANK YOU for the head's up on the limitations on the upscale unit.