Hi Elliott, This is a great breakdown and very generous in sharing your process and insights, you came a long way from the vending machine days!
Are you planning on releasing the UE4 project to the public? Or only builds? I'd love to play around with it in the editor if possible!
Daniel Thiger has recently become the first artist to release Signature Series for Substance Source. The artist has created a number of wonderful materials that cover 3 different biomes.
You can learn more about the initiative here.
You can now learn how the artist created one of the materials, Iceland grassy cliff, with a new webinar. Join Daniel and Wes McDermott to get tips and tricks on the creation of high-quality materials, and start building your own substances.