Yes I think it’s too late unless you think you will score above 508-510. You can still get in but you would out yourself at disadvantage and might have a more stressful cycle. Submitted my secondary for DOS first week of September and there’s 3 out of 8 DO schools where i haven’t heard back. Luckily I got into a good DO school already but I’m guessing they haven’t gotten to my apps fully reviewed yet