Phone system asks "press 2 for complimentary upgrades, otherwise press 3 for everything else". Went with 3 in first call today, as I had to ask something else, and got Aussie agent. Pressed 2 next call and got overseas agent. No problems though... easily confirmed Business Reward availability on desired flights (I'd already done the research), waited while I finalised the Business Flyer booking and applied upgrade vouchers due to expire today to Flex fare. (Just went with Flex fare, rather than going with Choice fare and trying for the upgrade, as prefer having some sort of flexibility on base fare still.)
I guess if you pressed 3, are they going to transfer you back to 2 if you're just requesting an upgrade? Maybe, maybe not.