I believe it would be very helpful if the “next subtask due date” could be rolled up into a new default date field that is associated to the parent task. The current manner of managing subtask due dates is to manually expand each parent task and check the due date. It’s very easy to lose track of subtask due dates on both the List and Timeline views due to this.
If there was a new field “Next Subtask Due Date” next to the parent task “Due Date” that automatically updated based on next soonest subtask due dates, this would make subtasks significantly more usable.
We are currently manually managing this with a custom field and it’s quite burdensome.