Currently, the extension still needs a lot of work. As it stands, it functions like the existing CheckUser extension (not globally), except it uses a different table in the database. However, it took me about an hour to figure out how to get it working at all. There are a number of edits that still need to be made where the code references the wrong DB tables and columns, as well as other problems.
I've decided to investigate an alternative method of doing this that can be done without creating more database tables, or at least, not duplicating the existing cu_changes table.