This turned out to be a little harder than I expected. Layering 3D textures on top of each other in a way that let's them be toggleable was a bit less intuitive than I had hoped.
I mainly wanted to match most of the customization options from the original Whitemane's Inquisition, including nipple piercings, pubic hair, and face paint.
The piercings and face paint I'm generally happy with, but I'm probably going to tweak the pubic hair art a bit more to make it pop.
I also attempted to add a foreskin option as an extra model on top of the shaft. It didn't look great because it left a noticeable seam despite my best attempts to blend the textures. Instead, I'm going to look into adding foreskin toggle as a shape key to the shaft model or as a separate shaft model altogether.