Why not try out this idea and see if it’s feasible? WDYT?
Could you elaborate ? I'm not sure to understand it. You mean using JS to will be translated into native ?  

Sorry if I’m not clear, that is not what I meant. What I meant to say is when you want a fast native UI, but want still want to do as much as possible cross platform. So using javascript for all the business code and have a small layer of native UI that call the javascript, on all platforms.