You are absolutely right! There is nothing procedural in Nomad renderer.
But a stupid Matcap, I guess I draw it by myself, and some curvature settings are coming already very close. Well you know what I mean with close.
It’s not comparable in technique, everything is more sophisticated in your render, but the general look is good enough to make it hard to say what is done in Nomad or in blender……if you see it on a cellphone Instagram post without zooming 
Some looks with matcaps, AO and curvature
Edit: why not rendering a Matcap in Blender and share this with us? 
It’s a lovely look. I tried already hard to get close to your look - I am close and light years away….