it’s not out of the question.
I would REALLY love it if you could add it, though I also love that Mila can become a slime girl, just a shame that she can't stick with it for the duration of her quests afterward, since i'd love to have her be able to permanently transform into a slime girl, but then I guess the remaining CGs would obviously be incompatible, so I guess it's a given that the option isn't there for her to be a permanent slime girl for the rest of her quests/side quests, ah well.
At the very least, I WOULD love some yurilicious romance routes since i'd absolutely LOVE that...! <3