The flow limitations would indicate you need a slightly higher pressure.
Also, as long as you are comfortable with EPR set to off, then I think that's a good move to keep clear airways in check.
You are going about it the right way...by raising minimum pressure slowly.
"felt starved for air at 4 and 5" I found for me that I needed 5.6 as a minimum. Set the pressure, put the mask on with air going, lay down and relax, breathe normally and see if you get that feeling-if you do up it a little until you can breathe without feeling starved. This is not therapy adjustment it is just getting enough air.
Then sleep with it and make sure you have not jammed up you numbers, doubt you will, but always check.
The waiting a week or two or more is to keep you from whiplashing yourself, you need time to adjust to this stuff, but IMHO not enough air is not something to get used to-pressure in all its forms yes, lack of air no.
Since your pressure needs are below 10, I would suggest you try a constant pressure of 9cm with EPR at same level. Do this for 10 days and evaluate.
In APAP mode, resmed is very aggressive with pressure changes and they may be messing with your sleep architecture. Consequently, your AHI/RDI numbers may look good but you still feel like crap in the morning.
Started APAP 4-20, Closed range to 7.5-14, then straight 8.0 w/ Aflex 3
RDI always below 1. But sleep much much better at straight pressure.
Started on F10, Tried Quattro Air successfully. Finally settled on P10.