Yes, I would love to be able to copy or import a long list of subtasks into an existing task. I have frequent tasks that require same list of subtask with different product details. I would love to create a task template (not attached to a project template).

This could also help cover the milestone request, especially if updated subtasks are given checkbox functionality (essentially subtasks within subtasks). https://feedback.withmoxie.com/project-management-feature-requests/p/add-project-milestones-stages

Adding one more layer to the heirarchy (projects> tasks> subtasks > sub-subtasks) means original parent tasks could be used as milestones.

Yes. Use sub-tasks all over my projects.

Yes, this is key if more than one person is working on a task or if assigning part of a task to a client. Please.

yes please

This is a feature that I'm missing from Basecamp.

And also to have more ability to add as much information to subtasks as needed.

I agree but I rather keep simple checklists and just allow tasks to have the option to be dependent on other tasks. This way we could create a chain of tasks which would show the flow of the project better and allow for better estimates of the project as a whole especially if the timeline can take into account different people assigned to the task and what other tasks they may be assigned.

I would also like the ability to create milestones (or stages) in a project so I can organize my tasks better (as my projects usually have at least 40)

This would be amazing and I would be able to ditch Asana for project management.