SSR Mirror surface - Ignore UI / other objects

I’m working on adding a mirrored surface into my world, it wants to reflect everything normal but ignore some elements (I.e player UI).
Using SSR within the mirrored surface, but not quite sure how to set some objects / materials as not producing reflections.

An isolated example Unreal project I’ve put up ony my Github: https://github.com//TestReflection

Any help would be much appreciated.

Thanks!