I was going to head towards the same setting of 10 cmH2O, only over a couple of days, to minimize the abrupt change. I would not have dropped your starting Ramp pressure to 4 cmH2O. I would suggest you put ramp back to minimum of 7 cmH2O,,, a minimum pressure more comfortable for you and most adults.
I would then suggest to increase Ramp by 0.40 cmH2O every third or fourth day to gradually increase your ramp pressure to equal your CPAP pressure.
After a couple of days at these pressures depending upon your OSCAR Reports.I would like to
possibly gradually decrease the fixed CPAP pressure by 0.40 cmH2O to see what effect it has on your CA, OA, Re & H flags. I will probably be adjusting your EPR at some point. All in an effort to see if we can provide some relief for your sleep.
You earlier ask about APAP vs CPAP. My reply was that I prefer to think of them as a "Mode" of operation as some machines are capable of several "Modes" of operation. well guess what. Your machine is now in CPAP Mode as indicated on the left hand panel. just below the Orange colored AHI Banner.
Just above your Orange colored AHI Banner, you will notice several Tabs labeled, Detail, Events, Notes, Bookmarks, & Search. If you were to click on the Events tab, it will open a list of your events, You've never seen that Yellow Event Flag RE, before. If you click on > preceding the RERA category it will open up to show the time listing for that event. By clicking on that event it will open a zoomed view of the time around that RERA event. If you have the stamina and can comfortably play around in the Events Tab look at some of your other events, try looking at the zoomed views by clicking on individual times of events.
If you look at your Flow Limits graph just below that flag, you will notice the Flow Limits bar is up to ~0.33. I believe that may be resultant from "Chin Tuck" and/or resultant from your jaw going lax as you stated in your opening post. "
My lax jaw can shift out of place, causing facial pain and difficulty with masks", perhaps before the point of causing pain and difficulty with your mask, you will now see some RE Event Flags. Just another little troubleshooting aid.
I still suspicion that some of your CA events are linked to Flow Limits, We have time to try several different pressures and settings.
OSCAR is a very powerful tool, that is why many of us prefer to work with it.