(I added my GPA and award given from the NCOA commandant from BNCOC on that NCOER).
You should not do that. It is already on your DA 1059 stating your GPA and if you were commandants list or honor/distinguished honor graduate. Since while you were at school during that time, it is unrated time and your 1059 covers that unrated time on your NCOER.
In all actuality if you do use that on your NCOER, it is using the same bullet twice on one NCOER because the exact same information is on the DA 1059.