I have taken my gear all over the place, I pack my gear and if checkin ask questions, I answer them in most favourable way possible...
i.e. I put two boards in coffin bag (if asked that's my board with some clothes)
My sail bag sometime 4 sails, boom etc, (if asked that some sails and more clothes)
I try to avoid a discussion about windsurfing, its just surboard and some sails...
Never taken gear to maui, but I have heard and can understand that its one of the few places in the world where the check in staff know what windsurfing really is.
My advice is put roll the extra sails in the same same sail bag, and put the extra mast in the same mast bag, You might find you now have just got one sail, one mast, and one board each...
I would say your less likely to have a problem on the Australia side, than on the Maui side,