I also did a custom confirm admin pin setup where replaced confirm admin pin with a prompt for pin which is used to check against users table and if can confirm admin pin allowing manager y to confirm void on user a ticket without user logging out and logging the username of the user who confirmed admin pin.
You could probably just create an order state and assign the current user within the default void rule. Personally we track all voids, gifts, and comps based on an entity type for the server and custom reports. Pretty easy and works fine for our needs.