After initially install USS , you can login USS UI as casmadmin and can see "Data Source" so that you can do catalog and USS integration configuration , also service desk and USS integration . But after USS is using EEM for authentication , you will no longer be able to login USS UI as casmadmin unless your LDAP has casmadmin.
How grant user with the same privilege as casmadmin user is having in USS ?
Service Catalog 17.0 and higher
So any user who belongs to that group "openspaceadmingroup" will get the USS administrator privilege. In your LDAP , you will need to have a group called "openspaceadmingroup" and have some users belong to this group. Then, after your EEM is hooked up with LDAP, those users who belong to this group will be able to have the same privilege as casmadmin used to have.