If you have a performance problem and you only target one OS, using React seems more like a band-aid than a real solution. I assume your app is currently written in javascript, because I don't see any other reason to use React for performance.
I think you should consider moving away from JS, it will probably save you from future problems.
It was originally supposed to be (and built as) a web app, but it's only being used inside a corporate network (yay requirements). So that defeats the original purpose. Might as well make a desktop app.
I think you should consider moving away from JS, it will probably save you from future problems.