This is a life saver. After finally going over all the errors I'm seeing in WMT, it occurred to me that I had sections on the site that were not viewable to guests that had tags and when Google would try to crawl them, they would end up with a 404 error. I've since removed the ability to tag threads in these sections and now using this tool. Nearly 600,000 tags in sections that were for members only.
The process for going through these 600,000 threads is slow. Started 5-10 minutes ago and only through 4,000 out of the 48,000 I started with. Will start the over 500k tags once this one is done.
Thank you! I hope all is right with the world once this finishes these batches.