Sorry to go against conventional opinion (again!) but my opinion is : Wild diamonds are gutses! They eat a lot. They have a lot of food available, the area they come from is quite rich in snake food and has been since before European settlement. However, as No one says, they do have a fairly long cooling period. I'm not suggesting power feeding, but the same feeding regime as a coastal or inland is what I would use. We get no diamonds up here unfortunately but all the snake rescuers I know from the Sydeny region who I have talked about it with reckon Diamonds almost always have food in their guts when relocated. I certainly have no problem with feeding every 3 weeks, I reckon any Australian python will do just fine if fed in this manner, I just don't reckon it's necessary.
BTW, 2 large possums would weigh about 5 or 6 Kg, equivalent to about 20 - 25 very large rats or one every 10 days or so during feeding season.