I think when you have a task with multiple subtasks where they are not all due at the same time it would be much more intuitive to make the parent task default to be due when the first upcoming subtask is due. Then once you check off the first subtask that is due, the parent task should automatically change its due date to the newest upcoming deadline in the subtasks.

Without this feature I find that subtasks only cause me to have to click one extra time to view them whereas with this feature I think it would make them 100x more useful.