yhuchs
Fixed in new version 0.1.3. Thanks for the report.
I don't know how can I override UserValidator.php, because my extension doesn't use it directly (registration / creating user is part of core) . Override Register.php it's easy, because I use it in controller, but when the registration is complete, validation will probably fail (UserValidator.php).
return $this->response->make(
...
function (Registration $registration) use ($user) {
$registration
->suggestUsername($user->getNickname())
...
}
);