To determine the effect of pressure on your flow limitations use fixed pressure like Sleeprider recommended then try a higher pressure to see if it reduces the flow limitation. You could start with 8 cm pressure and then try 10 cm. The best statistic to use to see if there is any change is the 95% Flow Limit. value with lower values meaning the flow limitations are better. Flow limitations will vary night to night so you will need to collect multiple days of data at each pressure and then average them to get an idea of whether or not there is any noticeable change.
Flow limitations like this do not necessarily cause issues or symptoms and therefor treating them doesn't necessarily improve your sleep quality. Increasing pressure can have negative effects on sleep quality so you need to try and determine if the changes in pressure are actually helping you feel better or not. There is no statistic you can use for this, it has to be based on how you feel.