I do love breast expansion also but this game is giantess focus. When I said Trishka will grow bigger, I meant she will be taller. There is a subtle mention of BE during Trishka story when MC question her about her breasts size and she mentioned the breasts did overgrown the rest of the body proportion, she used to be a "DD" cup at normal body size.
Some peoples asked me about BE and other fetish on other forum. I could add specific path for those fetish but it's unlikely I will add them in short term unfortunately.