Another thought....have you actually had an allergy attack since starting the machine? Are you just trying to plan ahead for "just in case" with the FFM?
You know it is entirely possible that with the added humidity and additional things that can be done to clear the nasal passageways that the allergy attack can be managed well enough you can still use a nasal mask.
Even a little mouth breathing leak might be preferable to an AHI in the 20s. These machines can compensate fairly well for quite a bit of leak no matter where it comes from. I have an example some where of some known mouth breathing leak and it actually was quite minimal and well within the machine's ability to compensate. I was awake when I did the mouth breathing leak experiment...so I know that mouth breathing doesn't always mean MASSIVE LOSE ALL YOUR THERAPY big leaks. I have proof.
Your aerophagia issues really complicates the situation. You may have to be willing to maybe compromise a bit on leak management and AHI vs having AHI in the 20s with a FFM because you need a lot more pressure with the FFM but the more pressure also creates significant problems. We might have to think about which problem is a worse problem and let something slide a bit. I have had bad aerophagia twice in my cpap life. It's a horrid experience I would only wish on someone I hated with all my guts (
and there are a few that qualify)....so I totally understand wanting to avoid it.
At least until down the road you maybe work through Zonker's routine and work your way up to being able to use higher pressures without it causing major aerophagia issues.
I may have to RISE but I refuse to SHINE.
If you want to try the Eclipse mask and want a special promo code to get a little off the price...send me a private message.