It would be very powerful if you can display multiple documents in a workflow, basically the concept of a binder. Currently related documents is the only way to do that which requires toggling back and forth between screens. It is often necessary for an end user to see multiple document types to make a decision in a workflow task (It could even be documents in a different filing cabinet.) Additionally documents may be added to a filing cabinet downstream as part of a business process that need to be viewable in a workflow task.
The ability to select or filter which documents in a binder are shown at a given task would also be helpful.