Thank you so much for this guide, it has helped me retrieve a Pokemon Sword save that was lost (stupidly) during a profile transfer. Recuva worked for finding the deleted save file, and it is confirmed working in Yuzu, so I know its at least still in existance.
I'm having issues with the repacking part though. I'm guessing its a problem with the keys, as I do not have the sept folder. It seems that the Kosmos Defaults build is no longer provided through the tutorial link. Is there a more up to date method of getting all the correct keys?
Edit: I figured it out.. I had a folder mislabeled in my hacktoolnet folder. "Save" should have been "sav" lol. Can confirm everything else worked exactly as intended!