As the title suggests, increasing the slider maximums significantly for body parts (Especially penis/breast inflation, or allow the user to edit the base size, bonus points for allowing the user to import genitalia from external models) would allow for greater customization. We already have the ability to import other parts, and fans of Hyper might be left slightly disappointed with the current maximums for penis and breast size, while Inflation fans might want to push it even further. It would be ideal to have the sliders go to hilarious extremes, then the user editing the actual character model can decide where they want to draw the line, rather than being limited by the software.

I was messing around and was a little disappointed where the slider stopped, and there's no way to bypass the default slider limit that I can think of besides trying my best to hide the default genitalia and importing a model as a "part" after editing it in Blender.