Assume OZ "F" fare SFO-ICN-HKG-BKK with HKG-BKK in CX F. Ticket on Asiana e-ticket stock. Ticketed as 23 hour connection only in HKG. Passenger calls CX in HKG on the morning of the HKG-BKK flight and asks to be changed to the flight leaving 3 days later.

Will CX see the passenger in "F" and just make the change?

Assume CX would not have access to the fare rules, so nothing to lookup. Will CX be able to the the /X HKG in the fare construction on the e-ticket?

Does CX need the segment re-validated to 3 days later or will it accept the e-ticket without re-validation? Can CX self re-validate the e-ticket segment as the operating carrier?