You might try out some mileage totals using the "free" North America connection to/from South America, e.g. HKG-xJFK-EZE/GRU/SCL etc. followed by putting North America after South America, e.g. HKG-xJFK-EZE...GRU-JFK-YVR... etc. I can put some itineraries together that hit close to 60K miles/90K EQP.