RE: RERA [help understanding them]
Going from a soft cervical collar to a chin strap could allow more events. The reason being the chin strap won't prevent your chin from dropping down and 'cutting off your airway. The difference between an obstructive event and hypopnea event is a 30% change in air flow. So it's not much of a change really. I wouldn't increase the pressure to 10cm unless you see an increase over several days. You really can't just go by one night.
RE: RERA [help understanding them]
You have low OA and most of your events are hypopnea. My recommendation si to set your pressure to 10, and use EPR 3. That should be pretty comfortable (10/7 pressure) and should help treat the hypopnea and flow limitation. The only reason we might suggest an additional pressure increase is if OA becomes more prominent in your events.