SystemInformationMBS Username confusion

When I got my current computer I created as first user “beatrixwillius” as usual. I had the idea to use the migration assistant which wanted me to a second user “beatrix_willius”. This shows up in Finder as “beatrixwillius 1”.

For loading a LaunchAgent the SystemInformationMBS.ShortUsername works fine. For whatever reason unloading the same LaunchAgent wants “beatrixwillius 1” instead of “beatrix_willius”. Both UserName and ShortUsername are “beatrix_willius”. How do I get the other name? Or do I just use

dim f as FolderItem = SpecialFolder.UserHome

and then the DisplayName?

Sorry for the mess with your users.
You may want to merge the users and fix the user database on your computer.
Normally migration assistant creates them, so no need to do it yourself.

@Christian Schmitz: that sounds about as pleasant as a root canal. Besides, my app needs to run for screwed up users, too.