I’m curious about performing the NAND backup. When you first boot into recovery and use your favorite OS to perform the backup, does nothing of that leave any trace in the console itself?So I believe I see 2 main questions being posed.
You can try calling Nintendo and have them unlink it for you if you give them a legitimate reason such as losing the console, having it stolen, or selling it to a friend.
No it is not. The only way to return a console to its pre-hacking state is with a NAND backup that was made in Hekate before performing any hacks/CFW/homebrew on it. Without that, then your console will never be 100% clean even with a factory reset.