I have a couple of them in pots, got them pre-germinated off eBay. Germination is hypogeal.
As for the question, I had looked into air-layering myself. Apparently, air-layering Araucarias gives poor results. I couldn't find if it could be done with terminal growth without killing the tree, and lateral branches keep their lateral growing characteristics once air-layered. I just decided to go the long haul with seedlings. 15 years to get a crop might seem a long time, but it's much shorter than the South American Araucarias, which can take 25. Plus, it handles heat better, as far as I could tell.
Also, I looked into dioecy issues extensively, and while a couple of sites differed (without giving much evidence), the general consensus was that the trees were monoecious. Any two can give a crop together, and there were even reports of isolated trees producing a crop. That's another advantage to the SA ones.