will there be an opportunity to unlock a futanari evolution to give access to even more options?
You're in luck! , this has been recommended a few times. It was also added to the possible to-do list some time ago.
You can check it out here: https://www.patreon.com/posts/next-update-to-83683143
It is a public post, you can bookmark the page if you want to keep up with what's being worked on. Futas has been something highly recommended, so in the mean time, there's 3 futas in the game, and one of them (Talia) has 2 scenes.