I was very aware of my apneas. It was horrible. My apneas were combined with sleep paralysis. Suffocating but struggling to wake up. My sleep apnea is also connected to night terrors. With cpap I sleep peacefully!
My apneas are not limited to back sleeping. I had them in all positions. Also during my during my sleep study I never reached REM sleep.
So sleep apnea is not limited to back sleeping or REM sleep.