I have UARS. My first sleep study about 1.5 years ago indicated severe sleep apnea. My second sleep study about 4 months ago indicated "maintenance insomnia" with arousals. My third sleep study about 2.5 months ago indicated "very loud snoring" and about the same thing as the 2nd, with the exception that the 3rd sleep study was done with a different clinic (all three were different from each other). My ENT interpreted the last two sleep study results as UARS.
Now, I've been exercising with a breathing exerciser (not a medical device, but it's mainly for sports people) for 2 months (2 more remaining) to see if fortifying my throat muscles will help. I've been on a CPAP machine all this time. It wasn't quite helping me in the APAP mode, even though it was recording "very good AHI". But it started to help me in the CPAP mode (fixed pressure) at 9-10 cm H2O.
I have also tried a very expensive (had to pay about $3000 CAD) mandibular device from SomnoMed, but it turned out to be much less tolerable than CPAP for me.
If in 2 months the breathing exerciser doesn't cure or noticeably improve my condition, I'm going for CAUP surgery with my ENT.