Yes, I created a feature proposal. Will update you if I can work out something with Codex. We have to be careful which fields we allow this for.
If the whole column is empty, you can simply not import it. You can keep it in the csv that generates it, but you can skip it in the import template. But of course, if the column is partially populated, this does not work, as the fields that have nothing between the separators will also be overwritten.