Even a broken clock is right twice a day.
Not a problem at all, but you might get a look from the CM when you tell them your "John" Smith.
"Work" might be too strong a word, but I'm usually hanging around the party a couple of times a week. Anyway, believe it or not, the phone CM is right, it doesn't matter. The check in process is low tech.
Working off a printed guest list, they ask for a last name, first name and confirm the party size. Then they turn you over to another CM who gives you credentials with a lanyard and also bores you with a spiel so that everyone realizes what they're in for. No verification or ID required. As long as the name is on the list, you're in.