Let me share a little story about myself.
Many years ago (like the 1st year of my being on cpap and it's been over 13 years now) I did an experiment to see if I could get the AHI any lower or change how I felt or anything..
I had already figured out that a setting of 10 cm minimum with the range going to 20 (my OSA is documented 5 times worse in REM so in REM I see much higher pressures in the mid to upper teens). My AHI was running somewhere along the lines that yours is running...sometimes a little lower and sometimes a little higher. Usually running between 1.0 and 2.0 though.
I decided to start increasing the minimum 0.5 cm at a time and give each change one week to see if anything changed.
So devoted 6 weeks to that experiment.
At the end of the 6 weeks, and after spending a week at the minimum of 13, I reviewed the past 6 weeks results.
Nothing changed at all. Same amount of sleep....pretty much still had the same AHI...same energy levels...nothing changed at all beyond very minor small changes that happen from night to night anyway.
So I decided to abandon any further experimenting with higher pressures.
I had 2 main symptoms of OSA go away pretty much immediately and those were nocturia and killer morning headaches but the overall energy levels I wished would improve to reflect the AHI I was seeing but they just didn't change as much as I wanted them to change.
As I reflect on the experiment now I realized that I was having unrealistic expectations as to what a lower AHI would or could do. The therapy itself was working and working quite well. No more getting up to pee ever hour on the hour with a painfully full bladder and no more killer morning headaches from the low oxygen levels during the night.
The energy thing...well there were other potential reasons from pain to BP meds to just not getting enough sleep and some days are good days and some days are bad days still to this day.
As for what minimum to use...most likely you could do well with anything around 14 or 15 or 16 and I would suggest just pick one and stick with it for longer time frame.
One other thing....you probably should learn to distinguish arousal vs asleep flagged events.
It's very possible that your AHI while asleep is lower than you think because of potential false positives being flagged.
Increasing the pressure doesn't help reduce awake/arousal related flagged events.
You can have false positives in any category of event. Go here and watch the videos and learn how to zoom in and figure out awake vs asleep and while they are talking mainly about central apneas ....it can happen with any event category.
I have learned that most nights my AHI will run anywhere from 0.7 to 2.0 or 3.0 and without exception about 75% of whatever the AHI is...will be from false positives and I am not asleep when flagged. The asleep AHI is quite low but some nights I don't sleep so great due to pain or stress or insomnia or whatever. No amount of tweaking the settings is going to let the machine fix my problems with pain or stress or insomnia or whatever.