So just for those curious, any shipment that is not with your own luggage on an airline is considered commercial. Lots of hassle for that. Personal consumption one can bring up to 50lbs of meat back provided they can document it was from Australia. It seems that showing the passport is enough, so a documented hunt with photos should be sufficient.
As for bringing 50 lbs of meat back, I bought an RTIC cooler. They may be "better" coolers out there, but the RTIC was the lightest weight modern YETI style cooler capable of holding product frozen for multiple days. It weighs 21lbs for a 52 quart cooler. My plan is to deep freeze the filets and bring them back home. I should be able to get them down to 0 degrees F and they would still be well under 32 F by the time I get back in the US. The airline limits me to a max of 70 lbs for any single piece of luggage, so I should be able to get 49 pounds of my 50 pound allowance back home.
I leave in 13 days. My plan is to add a trophy bull to my hunt and have the horns copied to modified to replace the boss on my Cape buffalo 3D archery target so that I can have an Australian water buffalo target as well.