ActiveDirectory and LDAP should not switch to `CaseSensitiveEmailAddress` if they are relying on the default LDAP query `uid={0}` as the `uid` field in LDAP is a case insensitive field. Only if you are using a non-default query based on a field that the LDAP schema says is case sensitive should you consider the case sensitive version.

OpenID should be offering `CaseSensitiveEmailAddress` as a choice however as you cannot assume that the remote server is not case sensitive