So far I've seen those hook wrenches used for other things like bottom brackets, but haven't encountered them on a headset.

You could probably replace the entire locknut with a non-threaded spacer, or a stack of spacers.

Personally I dislike the steer tubes with the grove for a lock ring. If the ring should twist while trying to remove it, it is quick to chew up threads. It also creates a weak spot in the steer tube.