Does anyone know if the 14 day advance notice to print & mail a SWU cert. for an LH flight a "hard and fast rule" or a guideline as to how long it might take?

Our TA is trying to workout an upgrade for my boss on an LH FRA-LAX flight on 12/1. She booked the flight a couple days ago, and just last night called us to get an address to have the cert. mailed to us here in Europe. I honestly think its not gonna get here in time, but she seems confident. She is also claiming that as long as he has the cert in hand at check-in he "will get the upgrade", but my understanding is that its standby only?