Yes indeed! That actually works great, and I've now cancelled my AA reservation (60,000 one-way), and switched to the same flight for 20,000 BA miles. (Although I don't have any BA miles--and didn't even have a BA account until an hour ago--I do have about 100,000 Starwood points, which means this only costs me 35,000 SPG points, including the 5,000 bonus for transferring points.) 40,000 BA points (i.e., 35,000 SPG points) vs. 120,000 AA points. Thanks!

IPC is easy to get to via BA miles....
 

In regard to your earlier comment re difficulty of IPC itineraries, my wife and I used BA miles to fly JFK - SCL - IPC - SCL - JFK on LAN earlier this year. BA charged us 80,000 BA miles per person for travel in the new LAN business class, including SCL stopovers in both directions. We found the LAN business class product to be superior in virtually every regard.....

That's a fair approach. My point was more that it's hard to work in IPC if you're starting a *ONE* in South America (and trying to see other parts of South America) because of the two stopover rule. For whatever reason, it's harder for me to justify buying/redeeming miles for a separate ticket to IPC than it is contorting my RTW ticket to fit it in. Illogical, I know...