Currently there is no method to change the admin password once it's set. Appliance should provide a method to do this from UI/MC. Not being able to change password is a security risk.
Enabling RBS in an appliance to fix this is a work around, but not a good solution for a product that should be a stand alone appliance. De-Coupling iprint from edirectory like zenworks did many years ago will help this product have a much longer life. Zenworks allows administrators from LDAP sources and has a very solid user import and management framework. Why not leverage code you already own?