You can just undress them ...
X-ray is not undressing. Its the ability to see the insides of intercourse, basically being able to see the organs (dick and womb) interacting with each other.
Also talking about the customization.
I remember someone asking that question dev-s on Patreon and Steve answered with "No, we are not planning on having customization, due to how difficult it is".
Right now we have some sort of customization, but it really is just managing presets that other models have: textures and models of hair.
But what about Body shapes? Arent those customizations? Kind of but they are extremely minimal. You can make boobs bigger and thighs more thicc, but thats all theres to it. No different faces, no different eyes shapes, cant change the hight of hero etc. Also as if right now this ability to customize is only available just because its going to be in the sandbox mode. We dont know what part of it will make it to the main game. It may be possible it wont make there at all.
So I guess the more accurate naswer to cusomization question is going to be something like this: "There is going to be a very limited customizable parts of the character, but customization is going to be VERY limited. Dont expect to create some unique character. Your choices are going to be pretty limited". Now that may change in the future, but thats the wibe that I get from what we have right now.