I've only looked into importing cards automatically briefly. My feeling was that keeping progress might be an issue if cards change (and thus get re-created). Do you deal with that?
Yes, Ankify adds an ID to the front of the card so that on re-import, cards are updated instead of re-added. I'm careful about making changes to the MD file. The ID are only added to the front of the card so that the content of the notes are minimally changed.