Recently purchased the Resplabs CPAP pillow to help me with side sleeping and mask leaks. It has improved my abilities to sleep on my stomach and side without causing leaks or movement on my mask. It’s a little stiff when laying on my back but it might work itself in. I’d highly recommend this to anyone having similar issues as I had.
The pillow has 2 sides one designed for nasal masks and one for full face masks.
Side note I have a short beard so this possibly made me more prone to leakage.