Yes, it's possible. But if you're applying for a K1 or immigrant visa, the CFO counselor would be pissed if you schedule your CFO session before getting your visa on hand. They could cancel your scheduled session. That almost happened to me, but I pleaded with the counselor to proceed with the session anyway. We continued with the session, but I was not cleared. I was granted my CFO certificate only after I finally submitted a scan of my immigrant visa. So not much point in scheduling CFO ahead of visa issuance, unless you're in a great rush to travel.