ResMed S8 Elite @ 11cm (EPR 3).
Supposedly I have a setting of 3 for my EPR. As I understand it this offers the least resistance on exhaling. Makes it the easiest. The manual shows 4 settings OFF (no EPR)---1 (lowest EPR)--2— and 3 (highest EPR).
 My question is since my setting is at 3 is this working if the ramp is on? What about ramp off, is EPR still working? Does EPR kick in only when I reach my figure of 11cm or does it work all the time??
Appreciate your comments.  

A rather reliable source (at least they should be) responded to my original question saying, "EPR works at your prescribed pressure. Not during the ramping up to your pressure."
When you think about this, it sounds reasonable. The greatest exhaling pressure relief kicks in upon reaching 11 with my EPR of 3.  Put another way, after reaching 11 and EPR is 3, exhaling is restricted the least. (I guess I have trouble with the wording in the book when it says 3 is the highest. Looking at it again it could mean 3 is the highest setting offering the most relief.) I suppose the ramp gradually allows the pressure to build to its peak setting 11 and in my case with 3 EPR, then offers the least resistance in exhaling. Is this logical? I don't know.
Sounds good to me.