Welcome to the Community Forum, @anon87022309! 
Have you tried converting the form submission task into a subtask of the duplicated template task? You can drag and drop your form submission task to the duplicated template task. We currently don’t have a feature to automatically add form submissions to an existing task, I’m not aware of any upcoming similar options but I think the option to drag and drop the task to make it a subtask can help you!
Let me know if you have any follow up questions!