Advanced data importing question regarding subtasks

Hey @Matt5
I am afraid also this is not possible yet. I recommend upvoting here: Adding tasks to multiple projects via CSV importer

A workaround would be to multi-select in list view to multi-home tasks fast.

Or setting up rules can help. Even if you need different tasks added to various projects you could control the rule to trigger based on a specific section a task is in, a specific custom field selected etc