I would suggest that any disadvantage they might experience, and my personal opinion is that such is between slim and none, would be minimized further by the fact that USNA knows they are working with actual college level grades, not iffy projections of high school grades and SAT/ACT scores. Further, most of these candidates are repeaters and have assured noms from their nom sources. Also, as already mentioned, the action does not really ramp up until February. Finally, until the last couple of cycles LOAs were not that commonly used by USNA.