/SN didn't forget it could be turned off. Illya was said to be intentionally keeping it active at all times as payback for how much supporting Herc actually [i]hurts[/i] (childish but... the obvious) whilst /Zero was stuck with Lancelot being emo. xD

Can't comment on good writing, because... untranslated mobile game. With some vague idea that things should be accepted as canon or something because they're there, even if they aren't necessarily written or directly supported by Nasu... eugh. And if they are, then yay: canon lockout if you're not able to speak the language despite awareness of it anyway! One of my problems with CCC*. : D 

* Bathory and the grotesque Sakura things I forgot the name of are the other. :T