To be honest, the models the developer chose for this game are not the best choice. If you are targeting people who have a fetish for giant breasts, you need to understand what this fetish is. It's not just "dragging a slider in the character editor".
Big breasts must have their own physics, they must swing when a girl walks, they must fit tightly to any clothes a woman puts on, they must try to "pop out" of the bra, they must "flow out" from every side. The protagonist must be able to "drown" in such breasts, so that the breasts spread over his face and perfectly adapt to the shape of his hands. There is absolutely no question of textures interpenetrating because it kills immersion for people who have such a fetish.
Finally, we cannot forget about the girls' body shape. If a girl is going to have gigantic breasts, create a body for her that will allow her to carry such breasts. If you overdo it, which is very easy, you will lose weight from your breasts, you will not feel how heavy they are and instead you will feel like they are stuffed with air.