*sigh* They never, ever advertise a sysnand-only setup in their instructions, its completely user's fault if they decide to remove emunand. With emunand its safe and you won't lose a9lh.warning letting their users know they'll lose a9lh if they attempt to boot 11.4 in sysNAND Gateway Mode.
In fact you can disable firm protection on any other cfw, update your sysnand and get the same result.