This is the first time I've dipped my toe into the partner award pool.

Just snagged a couple J seats on SYD-NAN-LAX for June on FJ's A350. My understanding is that I can add a positioning segment on AS to get back to SEA; however, this didn't seem to work and the website kept saying nothing was available if I tried to extend the itinerary onwards to SEA.

Given how hard it is to find reasonable J space to/from Australia, and how easy it is to get from LAX to SEA, I just went ahead and booked tonight instead of futzing with the website to add the segment from LAX to SEA. Can I add this segment on for free, assuming there's award space available? Is there a specific booking class on AS that needs to be available to do this?

Thanks!