Trying to include IPC into the Chile trip.

Running into SCL-IPC issues.
I have NYC-SCL booked on AA (will need to change the award anyway for a fee, so looking to add to it).
Also have SCL-JFK booked on BA.

NYC-SCL-IPC and return is available on BA and IB for 112K Avios in J.

SCL-IPC is not available on either BA or IB for the same dates they show availabilty when it's part of the JFK-SCL-IPC itinerary.

AA doesn't see SCL-IPC segment, and even if it did, they tell me it's a different zone and a separate award.

Alaska doesn't see the segment.

So...I can book IPC-SCL-JFK on BA for 112K Avios, but I am not sure if it's the best way to go....
And even so, it still leaves SCL-IPC segment that's not bookable on BA because they don't see it, and not on LATAM because they don't allow one-ways.
Cash for o/w SCL-IPC is the same as r/t, $450 for Y.

The really weird part is that the SCL-IPC shows as available on BA as part of JFK-IPC itinerary, but not from any other origin...I was looking to see if I can book IPC-SCL-LIM or something like that and throw away SCL-LIm, but it's not available.

Any suggestions?