I have searched but not found the answer to this: my son is ticketed BOS-HKG R/T in October in J. I booked these tickets for him at T-360, but he has since moved to NY and would rather get on either the JFK or EWR flights if possible. Both are waitlist only. Can I waitlist those segments in his existing reservation even though the origin will be different from the currently ticketed flight? Or do I have to create a completely separate itinerary with two waitlisted segments and hope that both clear, then redeposit the original award?

Thanks in advance for any guidance...