I'd say in lieu of the world visit system and to prevent this type of action why not have future S ranks have invincibility when they spawn? It could be on a cooldown for a set amount of time (maybe like a min or two) or someone could use an item similar to Stygian Ash(for breaking Ixion) to speed up the process if they have it in their inventory.

You'd have the time of getting to the world and being there with enough time for the cooldown and also have enough time to tag it during the process. I know it may seem longer to get to then other S ranks but with world visit hunts being an issue there should be some way to allow everyone a shot at them.