Good point, you don’t want your in-game name to be the same as your creator id.
Neither do I, because playing ones own maps you dont want other players reaction be like “oh he knows all the secrets of the map, that’s totally unfair!”
I don’t know how it works, or why it is like this, but maybe it has to do with teams.
Like if several people are working under one creator code the individuals can still get credit for their maps, or something like that.
Just a guess, hope we will get an answer soon 
edit: Congratulations!!!