>>3665636I don't think her boobs ever changed.
Roboco was originally concepted as a player character for a shoot'em up game kuromaru9 was working on.
This could also explain why she has so many customizations, because the model was made in a certain way.
And as others have said, the model has been around since about a year before Sora debuted. But art of her goes back further.
There is a video of gameplay but I keep losing track of it, I'll send it here if i find it again.