[alexbaker]

Tasks exports json backup files, but editing these and importing them would not be convenient. You could synchronize with CalDAV or EteSync and look for a CLI client (e.g. https://calcurse.org)

[justaj]

Thanks, though now I see I can't create sub-sub-tasks and so on, so it's only hierarchical to one level only. Is that correct?

[alexbaker]

Sorry for the late response! Tasks supports infinite depth subtasks for offline, CalDAV, or EteSync tasks. Google Tasks are limited to a single level