Holy cow.. I don't know if you got something wrong with your unit, your headphones, or what... -15dbr in high mode on my stealth measures 90-100db average on modern music (janky measuring but it will likely be louder if sealed better). Some Daft punk as an example.
Maybe I am just too sensitive, but I gotta imagine at -15dbr your Arya's are a little louder. There's ways to calculate that out that i'm too lazy to figure out.
With all of that said, at -15dbr there appears to be plenty of headroom still. I'm getting pakes at -10, -11. about 60% and I feel this a louder than average album.
I did listen to it for just a moment and it sounded great but ouch

too loud for me. Maybe that's a me problem. I've never been a concert person so listening to loud music isn't a reference point to me.