Alternate method other than OMPF from NARA to find information any information on my fathers ship and/or service in WWII.

Thomas Clayton Stephens (dob 1/1918) served in the Pacific 1944-45. Is there information on the Notice of Separation (navpers-553) that might provide a clue(s) to his service? Form Box 24 shows:"USNTC, Ferragut, Idaho / U.S. Naval Station, Navy No. 3149 / Sumar P.I.". I have requested records through NARA twice in the last year. Due to Covid , they can only provide the separation. I'm hesitant to add to the workload by ordering repeatedly.