Unfortunately, when Nitrous was introduced it effectively 'broke' the 2 best viewport shaders available - 3pointshader and Xiolul - for displaying real-time/game assets.
I would like to see a native Nitrous shader aimed squarely at UE4/Unity look-dev(similar to what Modo recently introduced) Possibly a real-time environment mode in the viewport with .HDR lighting. And whereas the above mentioned shaders were previous-gen tech(diffuse/Spec) this would obviously be built for metal/rough PBR
I realise this can be set up using ShaderFX/Stingray but I find the SFX results to be pretty terrible.