Being able to set due dates for subtasks that are relative to the other subtasks would be so helpful. For example, when setting up subtask dependencies, if I could set the due date for the first subtask and then each subsequent subtask's due date be set to "previous subtask due date + 1 day" it would save so much time, especially when using templates. Additional this could work backwards so that you could set the due date for the last task and then all the other tasks could be set to "next subtask due date - 1 day".