The recurring tasks appear in the list section as a type of list. Show these also in the list of lists when clicking on the "add to list" button so that a task can be added to a recurring task as a subtask.

Although I can make any task a recurring task, I often have added a task during Start My Day that I think would be better as a subtask of a recurring task rather than a task or a recurring task itself, e.g. some kind marketing task that could be added as a subtask to a "Daily marketing" recurring task.