When the authentication realm is set to ldap plus 'authenticated users can do anything', the plugin is not able to create jobs for branches, giving the error below.

SEVERE: anonymous is missing the Job/Create permission
hudson.security.AccessDeniedException2: anonymous is missing the Job/Create permission

I've tried to mimic the elevated_privilege block on job creation, but I've never get a different message (in particular, no reference to SYSTEM user).

In fact, I guess that elevated_privilege does not work at all with that authentication configuration, because we have full read permisisons, and commenting out the privilege elevation code does not change the plugin behaviour.