The current implementation of the theme select came from when Pregnancy artwork and dialog was just completed, and there were artists lined up for Blueberry and Breast/hourglass expansion. At the time it seemed like I was lining up a lot of artists to add more themes, so I stubbed out some other possibilities to help plug them in later.
I made the game itself to be modular, so that as long as I got artwork for any kind of expansion or transformation theme, I could add in the artwork and story for it.
For my plans for release, I couldn't be happier that I have not one but three themes in the game. Although I planned for it in code, I wasn't expecting it. For now I'm releasing this game with Weight Gain, Pregnancy, and Blueberry for the expansion themes and stories so that I can keep to my already amended schedule for 1st Quarter, 2023.
I do have plans to learn Unity, probably with RPG Maker Unite, and with that I will probably see about remastering SoGIV. If that comes around and I can acquire more assets from artists, then I'll look to adding more themes that are requested.