A flight SCL-IPC-SCL on a xCIRC29SA would eat up valuable miles in the 29000 allowance very quickly - to the points that a decent itinerary may be impossible. Much better to get the cheapest return flight from SYD to SCL (or EZE if on NZ) and build the cheapest possible single or returns from the gateway city.

And since xCIRC29SA pricing is same /similar to xONE4 or xGLOB34, then it makes sense (to me) to focus on the GLOB which does allow access to more flights of interest to the OP.