As you said, firepoint, I doubt that they will add 777 to the fleet now that they expect to take delivery of 3 748 by the end of the year. However as far as I know the pallets for the main deck (high cube containers only, max 118in high) and those for the lower deck (max 64in high) have the same shape and dimensions for both 747 and 777, so they perfectly fit on either type.