Can we please stop calling each other names. It's not a productive way to resolve a disagreement.
To answer the original question, it will not be possible to reduce breast size for several reasons. There has been the aforementioned art asset issue. I would be required to redo the art for the entire game, which would result in several months worth of work. And as a developer I'm just not willing to commit that level of time to such a modification. It would increase the games reach, but I do not feel it would be a significant additional audience to justify that.
Secondly, large breasts are not just a visual feature, but a character trait. Many of the characters lives are changed by their breasts. One of the things I wanted to express was that being on the larger side of life is more than saying "my back hurts" every once in a while. Instead the way society treats the characters and how those characters accept their bodies are important to me. Essentially, they are not just big breast art assets, but big breast characters. Could that be done with DD cups? Maybe... but there are many women in the world struggling with K, L and M cup breasts, such that the traditional big boobs would ring rather hollow.
Yes the characters have exaggerated forms, but it is shockingly less than many people might think.
Of course all this is about my reasoning for why I can't create a modification on top of the game for you.
As for the abrasiveness of discussion, I would like to apologist for that from our end. As it has been stated, it is not infrequent that people come and openly object to the supposed prevalence of giant breast games. The fact is mega breasts are actually more of a niche than people might expect, most games listed tagged with big breasts are because there is one character with moderately large breasts. Really, a game not having the large breast tag is more a sign of a dedication to loli's than anything. The presence of mega boobs can actually be difficult to find when explicitly searching for it.
I explain all this because as a community we often find ourselves struggling to find games that fit our niche, while being told that we are the only people being catered too. This can result in the aforementioned defensiveness.