It seems with 2.0 the issue has changed. Now the badge/title can be set by admin and is the correct localized version.
But for the user the title setting is broken. If the user himself tries to set it in his profile, settings, it is not saved at all. If I change the translation of the name of the badge to “Regular” or set the locale to English it works.
What also works is when the change is done at profile, badges (is this approach checked differently?). But if you set the badge there and load the page again “none” is preselected instead of the current title. This is the same for the english locale - so it seems this page does not get the current title correctly.
The bug still exists in 2.0.1. And I found another one… even when you can select the translated value in the badges page, it is reset after a while. So I guess that a task that checks if you are allowed to have the title is also not aware of the translation and then revokes it?