I am planning on adding it in the future, but not sure how many people would be interested in it...
Perhaps if time allowed you, just offer a toggle on futa content? Unless it would be easier to do what others have done and make a futa exclusive version?
Personally here, I enjoy futa content, but in moderation. Need a mixed bag. A game of only futas has no attraction to me, but having a few futas as an option is thrilling.