Originally Posted by findark

JFK-LAX-SYG-CGK is fine for MPM as you note: 13,391 flown miles minus 2,000 for the LAX deduction and you are under MPM. This will price normally as long as there is no stopover in SYD (maximum transit time 24h00).

The HIP check comes into play if there is a stopover. If you add a stopover to a mileage (non-routed) fare, the fare component with the embedded stopover will reprice to the highest of itself, the origin-to-stopover fare, or the stopover-to-destination fare. So if you add a stopover to SYD, the price for RLE08MN2 is adjusted to the highest of:

RLE08MN2, JFK to CGK ($1,125)
INXQFVN1, JFK to SYD ($4,461)
and I believe since AA does not publish fares on SYD-CGK, that comparison is dropped