We can certainly look at adding it if there’s enough interest from the QuickFile community - it’s an open forum, so other users can add their comments and support to this thread.
I’m not aware of a bulk way to import credit notes, but I will ask our development team just in case I’m missing something. The issue I think with importing credit notes is that they often relate to something else (e.g. it relates to a bank transaction or is a reversal of a previous invoice).
I’ll update my post shortly.