Just done a test with material creations in Cosmos AI vs PixPlant 5… guess its in early stages? Cosmos Left, PixPlant Right BTW.
I am wondering where and how the Cosmos AI is to be found and used in the Corona UI.
"You can follow the instructions on V-Ray for 3ds Max - because this is all on the Cosmos side, instructions are the same across V-Ray, Corona, Max, C4D, etc. 
Basically, open Cosmos, choose Materials, bottom right you’ll see the Generate button."
https://forum.corona-renderer.com/ Ai Materials #msg235043
“HOW TO USE IT?
Using it is simple, for now just use the V-Ray guide at V-Ray for 3ds Max”
https://forum.corona-renderer.com/ AI Material Generator Playground #msg235017
The results don’t look too dissimilar to me - the biggest difference to me is that PixPlant has created displacement as well, so you could try using the bump from AI Mat Gen in displacement for now, and/or increase bump strength, for those more exaggerated cracks. And yep, naturally once developed, things will continue to be developed in the future as well