Can ExpectedDuration be used to manage DueDate?  

I put in a feature request to incorporate DueDate concept at the process level but noticed Workspace has ActivityInstance.OverDue.  Help has nothing on OverDue keyword.

If originator indicates a DueDate for the request a week from tomorrow, can you set it in ProcessInstance.ExpectedDuration then use API/SmartObject to pull/sort workitems that are close to DueDate?    Currently there is no feature to sort the worklist based on DueDate.