Without seeing what that AHI is composed of (each event category) I don't know about increasing that EPAP minimum because if it is mainly central more EPAP won't necessarily help.
Can you use DreamMapper and get the number of each event in each category?
SleepyHead won't work with your machine.
If you have a Windows computer we could get you Encore and hopefully get it installed (PITA to install) so you can see what that AHI is composed of.
Back door way is to use DreamMapper website and I think it will give you the total number of events in each category so then you would know what the AHI is made up of.
If it is for sure obstructive...maybe a little more EPAP but I would be very cautious. See this.http://www.isetonline.org/yahoo_site_ad ... 190318.pdf