Why do you feel that they need to be "totally conquered"?
Are the leaks and mouth breathing waking you up often?
22 minutes of large leak out of nearly 8 hours of sleep (4.66% X 480 minutes) isn't the end of the world if you are sleeping soundly and feeling decent.
It's not a real pretty leak line but we don't get extra points for "pretty".
Sometimes we sacrifice good sound sleep for "pretty" by trying to make chin straps act like vise grips or something.
If something we do ends up being uncomfortable and causing us to not sleep well or have difficulty falling asleep and/or staying asleep then the cure is worse than the disease.
What are your priorities? Good math scores and pretty leak graphs?
Or good quality sleep and feel decent with acceptable math scores?
FWIW...it took me about 3 months for my mouth to learn to stay shut. I found taping was less annoying to me than chin straps and chin straps don't always work anyway no matter how tight they are. Clinch your jaws together...now open your mouth a little and breathe...having the jaws clinched doesn't stop a person from opening their mouth and breathing.
Chin straps are meant to be gentle reminders to the jaw to not drop. They aren't meant to be vise grips.
You might consider adding a soft cervical collar to help support the chin. I found it annoying myself to have to wear something else but many people find it quite acceptable and comfortable.
Also...not all leaks are mouth breathing leaks. We can have mask movement leaks too and the only way to know for sure is to tape one's mouth and see if the leaks totally stop. I quit taping my mouth about 3 months into therapy.
A couple of weeks ago I was seeing some pretty significant leaks with a mask that I was trying and I needed to know if the leaks were related to mouth opening or mask movement so I taped for one night and the leaks were still ugly...and the tape stayed in place all night...so the leaks weren't mouth breathing leaks after all. They were mask movement leaks.