OP: What's the breakdown of the taxes/fees on the BA redemption? AFAIK, there are no carrier surcharges on LATAM tickets, so unless I'm missing something, BA should only be charging you the same $5.60 (which is the September 11 Security Fee) that Delta is charging for the JFK-SCL award on LATAM.

Edited to add: A friend who recently redeemed BA Avios for JFK-SCL on LATAM just sent me a copy of the cash breakdown. Apparently, there is now a $12 carrier surcharge on this route; that, in turn, triggered the U.S. international transportation tax, and the PFC. Still, a much better deal with BA Avios than with DL Sky Pesos.