The B777 is allowed to use 2 different flap settings for Autolands.
Flap 30 for normal operations
Flap 20 for non-normal operations.
Not approved for flaps 25.
A normal operations go-around (from flaps 30) would result in flaps 20 for the go-around. Both engines would be operating so climb performance shouldn't be limiting.
A non-normal operations go-around (from flaps 20) would result in flaps 5 for the go-around.
Oz