Our system uses "Calculated Assignment" as the default duration type for new projects. That setting is appropriate for the proof projects that are managed through Workfront.
However, for non-proofing projects, other duration types may be better. I have found that changing the duration type from Calculated Assignment to Simple of individual tasks, once the project has started, changes the duration of the tasks to 0 days.
I would like the ability in the Project Details, to change the default duration type, so that all new tasks in the project take on the specified duration type.