Yours is under the threshold to require therapy... You should have no problem pushing this, it is very clearly published.
But on the other side, I thought the same way at first (my dad has severe SA as well...) and I love my machine. I did have to turn down the pressure recently because of weight loss. The machine I got on my insurance many years ago and I'm actually using my dad's old machine because his insurance gets him new ones quite often. I should probably look into a new one because since having the surgery I probably hit my personal out of pocket limit and could get one for free basically.