Just one quick caveat before I start. I am not up on all the latest CPAP technology. My apnea is mild and I don't need any of the fancier systems. Unless I have a cold, I use straight CPAP with a minimal amount of CFLEX. So what I'm about to say might be contradicted by th current state of the art. If so, I apologize.
I agree with those who posted that a CPAP (of any variety) increases breathing efficiency. As someone posted, it can be very helpful when you have a cold. In my case, it almost always completely relieves my breathing problems when I have a stuffed up nose. I just increase the pressure a couple cm and set the CLFEX to the max and I can breath while I lie down. It's made a huge difference in how my body handles a cold.
It also seems like a CPAP could be configured to administer oxygen. When I started CPAP a couple decades ago my mask had ports. They could be used for administering oxygen. My current mask doesn't have ports and I'm not even sure that masks with ports still exist, but it shouldn't be hard to connect up an oxygen tank to a hose or maybe directly to the machine itself. My machine doesn't have any way to connect up a tank, but I'll bet there are some out there that do. Even if there aren't a little creative plumbing and a pressure regulator could do the job.
So I don't know if CPAP can be helpful in the case of a severe COVID-19 infection. But it seems like something worth considering. SO thanks for starting this discussion.
Only wise people learn from them