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!
CG artist Eddie Ataberk has presented his own useful Substance module that will help you create crazy radial patterns. And the most awesome part is that this tool is completely free.
Download the Radializer for free here.
Also, make sure to check out artist’s ArtStation page.