You don't really lose anything other than a bit of your time. Worst case scenario, you improve your application/essays and try again next year. You'll be more confident in yourself and you'll already have some intel about how USU's admissions process works. Best case scenario, you get accepted and don't need to worry about anything.
It's been said once but I'll reiterate because everyone asks about it. USU believes an MCAT score of 500 (or more) is sufficient supporting evidence of a prospective student's success in medical school. They care more about GPA (median is about 3.75).
The slots are more than likely not all full. USU has a strict budget and can't accept more students than their budget allows for (the class size is always around 165-175). Like other schools, USU values diversity and likes to keep their options open. They want to see what every student has to offer before finalizing the incoming class. It's not over until it's over, and the admissions cycle runs until July of next year.
Furthermore, this cycle doesn't seem as competitive as last cycle.
@PMWB2022 just mentioned that they were complete 10/4 (submitted everything in August) and got an II on 10/21. Last year, when I was complete in late-September, I didn't hear back until late December and interview until late January. Furthermore, this thread is significantly less popular than it was last year so there are likely fewer applicants.
Also, USU is one of those schools that will give you feedback if you ask. Use that to your advantage if things don't work out.
tl;dr You don't have anything to lose. Best case scenario, you get accepted. Worst case scenario, you don't get in and spend an entire year improving your application and essays using the feedback that USU gives you.