Awesome!! Congratulations man!
I do have suggestions to improve though.

you could add some new sliders:
- glans size (for "mushrooms")
- veins (set the start of the slider as no veins and the end to very veiny)
- penis color (most penises are not really the same color as the rest of the body, you could add a slider to darken it compared to the body)
- glans color (the glans is always more pink/purple than the penis skin, you could set the start of the slider to "exatly the same color" and gradually change the color over the slider)

also it is a little weird that the "default" state is hard and not soft, it would be good to change that (or at least create a "set default state" command).

and I dont know if it's possible, but it would be nice a command to stay nude in the game (not "nude clothes", like we find in most mods). it's almost pointless to have such awesome tools to customize the penis and it's only noticeable while showering.