No, are YOU for real? You thinks it's technical limitations that limit breast sizes and it's that assets would look stretcher? Or that the game engine couldn't handle big boobs assets? An incase you haven't noticed character creation in games usually allows you create all kinds of weird looking characters without it somehow hitting those magical limits that somehow apply to breast sizes apparently.
The breasts slider was just an example of "representation" not being actual representation and you need take time out and reflect on why big breasts in video games make you upset.