Mine is in the future and today during lunch I decided to make a quick stop at the ASC to try my luck. The place was deserted, just a couple folks. The answer that I got was no, wait for your appointment. I cracked a couple jokes, charmed the lady, and complimented her and her manager, and guess what? They let me do it. 4 weeks ahead of my appointment. Who said you can't sweet-talk an immigration officer? I was lucky I guess.