If you are having difficulty adding Font Awesome SVG with JS with CSS :before pseudo element then you are not alone. Here's how to do it:-
1 Load Font Awesome SVG with JS in the normal way
2 Activate the Pseudo Element which is turned off by Default
3 Add the CSS to your Stylesheet with a couple of Amends
That's it you can now use the :before Pseudo elements with Font Awesome SVG with JS as you have previously implemented in earlier versions.