Advanced Preview: Integration needed with the new GXT user picker

I have a LDAP directory mounted on my Jahia. I am using the advanced preview mode with one LDAP user. The User slection drop-down is not working (so I do not know if it should work or if it is not implemented yet). In all the cases, we should link this to the new GXT user and group picker (cf: ACL on categories or files with the user and group picker). This should be the same component (but perhaps limited to user picker only)