@AlanMattano
Can you share your experiences? Or links to the threads you made? 
My experiences with Rhino & Substance Painter are mixed… I ran into some obstacles. Rhino’s texture mapping compatibility with other software is crucial here.
I was using Substance Designer a bit, but It wasn’t always that pretty. Sometimes I tried to modify some bought SBS brick textures. I wanted to change brick pattern and always I run into some or complications with the data flow. As far as I saw, Grasshopper is superior among all node editors in terms of data readability and possible tidiness.
I am mentioning this because I wish that Grasshopper one day will be capable to do more in bitmap field.
SBSAR files are working great inside UE4 and I would happily see them inside Rhino.
That would be amazing, but as far as I know, it is not working this way 
Some comfortable way to make & adjust procedural masks inside Rhino, to blend between two variations of the same material would be a great thing to have.
@nathanletwory Is it possible to blend two PBR materials with procedural noise from your Cycles Grasshopper nodes?