1. Some TTE's are good and they usually let you adjust in the same berth/different berth (if vacant)
2. Some TTE's may quote a different rule and refrain the partially waitlisted passenger to board. In such a case, it would be wise to purchase a SF UR Ticket and then board the train. In an event where TTE may deny to allot berth against the concerned ticket, ask him to issue an EFT against the SF UR Ticket and allot any vacant berth for 2AC/3AC.