I have a low quality deck (basic fields and input data, no audio or other useful info) that I want to regenerate using superior card generation tools such as Migaku for Japanese or other add-ons.
Is there a way to regenerate the whole deck in this way, that is to say, recreate cards from the vocab stored in the expression field and auto-fill the other fields. The note-type is already correct, it just needs the fields filling.
I don’t have an on–point answer for you, since it sounds like you’re looking for automated tools or bots to do this work for you.
But this sounds a lot like using a shared deck as a skeleton to start building your own deck. You can do that yourself, so there’s no reason you necessarily need fancy tools. See also: Making a language-study deck: my workflow.
[Cross-link to your Reddit thread: How to rebuild / regenerate a low quality deck]