Temporary booking of 2 JAL award flights on same day to same destination
 

I had planned to connect in NRT from a Delta award flight to a JAL award flight going to BKK next summer. Delta will be changing their Tokyo flights to HND, and I can't make the connection there on the day that I arrive. I can, however, connect through Osaka KIX airport. Currently the JL flight has a business class award available from KIX to BKK, so I would like to book it now and not risk that it will be unavailable when I will hopefully be able to change my DL flight to Osaka. The consensus opinion is that this will not happen until November when DL announces their new HND schedule. Once DL makes the change to HND, I would cancel the NRT-BKK flight. What would AS or JL do if I book the KIX-BKK flight and also still keep the NRT-BKK flight for a couple of months? Would they notice? Actually the KIX-BKK flight technically departs the day after the other flight, as it leaves just after midnight, if that makes a difference.

Anecdotally, Alaska's IT is not very good, and they aren't great at detecting duplicate bookings.

AS might send out an email. Is it impossible to make it from BKK to KIX in time from when NRT-BKK lands? Yes, I've had AS email for duplicates before, including partner reservations. I've usually rectified this in a couple days. Once I think AS called me too. Its not usually intentional, plans are constantly in flux for me.

I think you have misunderstood. What I plan to do is change NRT-BKK to KIX-BKK because my flight into NRT will be changed to land in HND and not NRT. It might be possible to get from HND to NRT to make the original flight, but it would probably be cutting it close, and I would rather not stress out about making the only connection of the day to BKK on JL. I need to get to BKK on the originally planned day because I have a lot of other travel that would need to be re-booked if I don't.

I will keep your experience with duplicate bookings in mind before I decide what to do.

The experts saying that the airport change would be in November were wrong, as Delta just announced their new schedule. Problem is now resolved.