imo, this module would be more generalized if the 'Shared Editing' collapsing group (with 'add viewers' and 'add editors' options on the node form) was instead configurable and would work whether I wanted to add editors or viewers or both.

I'm trying to make a 'Message' node type have the "Add Viewers" display, but change the language to "To:" without any help text. And I would like to be able to uncheck 'add editors' display. This would be a very elegant solution for private messaging, while no other good one exists for D6.