I have been planning a LONE5 for the past few months and I "think" I have the best possible routing for our trip based upon Oneworld tools and this forum. Europe and OZ are the only destinations where we have some wiggle room with the only required destination being Rome. This itinerary works out to about 3700 USD per person after taxes/fees (but does not take into account we would have to buy a roundtrip to NZ)

Here is the validated LONE5 route with Quantas:

AUK-SYD > Quantas
SYD-BKK > Quantas
BKK-DEL > CP
DEL-NRT > JAL
NRT-LHR > BA
LHR-CDG > BA
Surface Sector CDG-FCO
FCO-MAD > IB
MAD-RIO > IB
RIO-SCL > LAN
SCL-EZE > LAN
EZE-LIM > LAN
LIM-CCS > LAN
CCS-MEX > MEX
MEX-LAX > AA
LAX-AUK > AA

We prefer that South America/Mexico are at the end of the trip, but have to get there within the Visa time frame required by Brazil (90 days)

Am I overlooking any better routings/cheaper options? A mileage challenge would be great, but we have only 2 AA flights on this routing.