Hello, thank you so much :)
Adding a room for a character, and everything that comes with it, it a huge undertaking. I do have plans for a third floor though. Originally I was going to add more main characters, but I can barely keep up with the plans I have for just the next main character. So I can't spread myself too thin. I'm currently working at my maximum capacity (when I have the time to work).
But I would like to include a lounge area on the third floor, a place where characters would hang out instead of the utility room. Interactions between characters can happen, it's an easy place to add games or other activities the characters can interact with. A gym might even be possible on the third floor. But I have plans for Eris ;)