I believe you're incorrect. First of all: https://developer.apple.com/app-store/review/guidelines/

2.5.6 Apps that browse the web must use the appropriate WebKit framework and WebKit Javascript.

The JIT thing was true, but a few years back, they lifted this restriction, see "4.7 HTML5 Games, Bots, etc." for its current incarnation which also says "your app must use WebKit and JavaScript Core to run third party software".