We use LDAP for login, but not for email address, we get users to sign up to Mantis with their LDAP user name but they can use whichever email address works best for them. This is no longer possible, while LDAP works much much better now (thanks!) we had to disable the LDAP login_method checks in both print_api and signup_page.

Going forward it would be nice if this was still a configurable option and respected the allow_signup value even for LDAP.