So wait, if you're editing the original image, wouldn't the result just be wrong? I'm genuinely confused. You edit something, you want to change that, you should be changing what to you edited it to, right? Isn't that the only thing that makes any sense, because if you were editing what you had before, the change you make wouldn't be right in the context of the new edit?
And if you want to keep something, this is why we have layers. Which Gimp has and just works. That's the real way to do "non-destructive editing".
Maybe just not understanding how things work in PS because I've never used it extensively, but common sense tells me that if you edit something, you want it to look like that and any further edits would be on what you edited it to, not some unknown echo of the past that would interfere with how the image currently looks, which is what you should be editing, right?