Hmmmm take an over 10m kite to Yorkeys. No waves, no need to turn the kite...aye.
I would normally use a 13m-20m when I lived there and also used those sizes when I lived in Port Drugless.
It was regarded a windier period then too. Elnina? Elnino? Dunno?
Well maybe not that windy cause my smallest poleboarding sail for NQ was a 5.7m and that would come out when it was windy!!
Only got over powered once on that thing, offshore at Green island.
Im sure you'll score a few days of wind, if you're there in August for the whole month.