The shader can be made with nodes, but you’ll need to understand how to offset the scene sample UV and the basics of refraction math and since it’s a screen space effect you’ll need to understand how to compensate for screen attributes too.
As I mentioned before, all of this can be achieved with nodes, but being able to interpret the formulas in the HLSL will help you in not needing to start from scratch - even if you cant actually write code. Math is math so the formulas can be ripped straight from the shader code and duplicated in nodes.
For example I believe the core of the shader is 1-IOR*(Pixel Normal) transformed into view space. The shader then adjusts for aspect ratio and resolution scaling, plus there’s some extra stuff to compensate for other things like what to do when sampling outside of the screen. Without that stuff, the refraction wouldn’t look consistent across different sizes screens.
But ultimately no, it isn’t trivial.