Do not allow editing username
With the new registration system the username is an opaque identifier, it shouldn't be editable, not even in /manage/
#3 Updated by Benjamin Dauvergne almost 5 years ago
The problem is storing the uuid in the username, that's not its place; any field should have only one semantic whatever the user. Work on access control contains a new user class with an uuid field, in the meantime we should live with this problem.
To ease manipulation of registrered user I advise using the
A2_REGISTRATION_GROUP setting with a default value of "Online registration". It automatically adds registered to a group named "Online registration". If we need to migrate those user to a new uuid storage in the future it will help.