Submitter in message directive accept only one single name, because String field usage.

input message: 'myMessage', ok: 'OK', submitter: 'myUserGroup'

You cannot i.e. use a list of LDAP groups (typical situation in organizations). For each input field separate LDAP group has to be created. This solution is not good, because flexible permission management cannot be based on single groups, but on the set of groups representing user populations.

Comma separated list has to be supported.