This isn't strictly related to React Native but have you considered using Flutter? IIRC it compiles to a "native" iOS app instead of doing this weird JS stuff React does.
BTW, never've heard of Flutter until you mentioned. Looking into it now. Looks cool, but... It's just been released? I do not want to depend on a bleeding edge solution when everything is at stake (I'm talking about a typical startup execution). I'd give it few more years before seriously considering it. I've seen the solutions that were supposed to take over the world (which never happened). SmallTalk, C++, JavaApplets, RubyOnRails. I'm sure I'm missing a few. While all these are very cool technologies, the "weird" JavaScript stuff is being the most used language in the world these days (whether we like it or not).
Flutter looks interesting, however, the same question applies to Flutter -- this is not a standard Apple's way, as such it may be banned. Why would not Apple decide to ban anything that is not Apple from their store?