I've heard that generally, once you get above the minimum OAR you should leave it alone as there will be many applicants with OAR waiver anyway. If you take again, you must be 100% sure you will score higher since they take the most recent one. How many LORs did you initially submit? I'm good friends with a career recruiter who mentioned that they typically don't want/need anymore than 4 LORs (quality over quantity). I can't speak much on appraisals though, no longer active duty. Good luck with the August board, I'm shooting for that as well.