Thanks for sharing the plugin, I liked it.
But testing I saw that there is how to make some improvements, at least for me in this case. Let's see if you like the suggestions and can see the changes in a future update.
- Implement SQLite/MySQL support; (Maybe for a future web page to display nicknames)
- Save the players nick histories by steamid and generate a unique log for the player; (I believe that this makes it even easier to find the nick of each player, and why not, saving everything in the database wouldn't even need to log)