Just to see if I could, I created a Breast Spandex morph for V4. It injects into her chest and abdomen and gives her that "stretched across her bosom" look. Looks very strange without a 2nd skin top! It was made for an unmodified V4 chest, your mileage may vary with other breast shapes and character morphs.

It's hard to see a great difference in the attached image, but there is.

I uploaded it to the Rendo Free area, it should be approved and posted soon.

I hope this proves useful to somebody.