TL;DR: Save editing is indeed possible for Shadows of Valentia, but it's a little more complicated than that.
So as we all know, SoV just recently was released in Japan, and was leaked even before the official JP release. Not much research has been done into saves, but theoretically, if it's anything like Fates, a save editor should be simple, right?
Wrong.
For some reason, IS decided to switch up the way saves were written, making them generally a headache to decipher. Here is what has been figured out about the saves so far:
Items:
Character Editing:
To be added later
Post any save editing discoveries you've made here as well!