Add an OIS Attribute Mapping service similar to the OIS Group Mapping service. Each backend would provide a list of available source attributes, and the service would allow selection to COmanage Org Identity attributes (similar to Enrollment Attributes, including types).
eg: The LDAP backend could provide "givenname", "sn", "email", and "uid", and then the CO Admin could map these to "name/given/official", "name/family/official", "email/personal", and "identifier/uid". Default values could be specified when none is found in the source.
This would replace each backend's resultToOrgIdentity (similar to how backends don't actually map to groups).
The mapping would need to be connected to an instance of an OIS, since the plugin might need to determine which fields would be available for each instantiation. For example, the LDAP backend might ry to query the server for its available schemas, and then present those attributes to the mapping service.