How to limit user access to Demantra Workflows?

Hi -

We want to allow users access to a limited set of workflows in Demantra.  We can assign workflows to schema groups and then set the schema groups to 'Private'.  However, it appears that the standard functionality is that all workflows are assigned to the 'All' group and we can not set 'All' to Private. 

Any ideas on how to accomplish this?

Thanks