Delta had no problem rebooking me FLL-ATL-SFO on the flights I requested. They also allowed me to upgrade to BusinessElite ATL-SFO even though the booking code didn't allow mileage upgrades. This was a courtesy move since we had originally been booked in biz class JFK-LAX on UA. Quite pleased with how DL handled the rebooking, especially considering how bizarre the original itinerary was.