Lovely hack - well done!
Not sure how hard it would be and therefore if you would want payment for it, but there is something else that could be included in this that I would find extremely useful.
Moderators upwards being able to set a thread to be ignored by a certain user. Obviously that thread would not appear in their ignored threads list, but instead in some listing in the Mod panel. This would be rather like banning from a thread, but actually be much more effective because that user doesnt get the constant reminder they have been acted against.
Simply perfect for members who have started an arguement on an established thread.
My site is non profit, but I would gladly fork some cash out of my own pocket to see this available to me and others.
Harley