[Exolent[jNr]]

That method is much slower and uses more memory as well. I don't see the reason to do it that way.
Also, you should use an if statement when jumping to keys in case it fails, even if you tell it to create the key when it doesn't exist.

if (KvJumpToKey(myKv, "Key", true))
{
    KvSetNum(myKv, "stuff", 1);
    KvGoBack(myKv);
}

That way you don't "Go Back" when it never moved in the first place.