The growth artifact is maybe a bit overtuned for the price, haha. I multiplied my growth once and the new flavor text went by so fast that I didn't get to see a lot of them. I'm really appreciating the new text though.
I think the weight gain maybe needs to be scaled down a bit though. I feel like the descriptions and the weight don't match up at all. A gorilla is around 350lb and the average human could use them as a beanbag chair. Average wrecking ball is 5000lb and 9.4 feet (113) in circumference. Since it's steel, it's way heavier than a titty would be.
In game I'm at 19 feet and around 10,500lb. That would make sense if titty was made of steel. Water is 1/8th as dense as steel roughly, and fat is less dense than that, so I'd lower your weight calculation by at least 1/8 if not more. So 19 feet of titty circumference would get you around 1300lb.
Oh a small note, A cup would probably weigh nothing. The model Miosotis as a 38 U cup and her boobs weigh 20.21 pounds.