DODMERB/Medical issues are not subject to the Jan. 31 deadline. That said, you should submit DODMERB requests for remedials as promptly as possible because they are needed for DODMERB to determine your qualification status.
Once they do that, if you are "not qualified," you are automatically considered for a waiver from USNA. USNA won't evaluate you for a waiver until they decide that they are likely to offer you an appointment.
You cannot be offered an appointment until you the DODMERB determination has been made and, if necessary, a waiver has been granted. Thus, as I said first, you want to be aggressive in addressing any medical issues but they are unrelated to the Jan. 31 deadline for other Admissions documents.