If you have ever tried reading constraints from an ECO model you have probably noticed by now that there are lots of auto-generated multiplicity constraints.
I personally like to add my own constraints for multiplicity so that I can specify a more concise error message
Customer required:customer <> nil
To disable multiplicity constraints you need to attach a .net attribute to your EcoSpace like so
public class ProjectManagerEcoSpace: Borland.Eco.Handles.DefaultEcoSpace