One of my pet peeves is so many games fall into the trap of dom chars have to have a dick and sub chars want to take a dick in a hole, when dom and sub are sexual preferences for control of the act not your sex itself. Most games that fall into this trap just make everything futa because its the lazy solution for this mindset.(A certain space text adventure comes to mind) Thankfully this game doesn't take the lazy route, but it does still fall into that trap. For example, Brax. If you turn him into a woman he just decides he's not a dom anymore he's going to be a sub now.
Its nice that this game lets you customize fetish preferences and transform people, but it kind of clashes with having almost all non random characters have set characteristics. I can understand some issues with transforming the characters race in some situations(Scarlett would probably be out of place at the nests if she wasn't a harpy), but fetish and sexual preference don't really have a reason unless you're going to write custom sex scenes.
And I think thats where the problem arises. The entire main framework is designed around this system of characters follow their preference so long as they have control. But custom scenes are their own separate framework with special positions that can't be changed and very limited actions. Instead of making separate fixed systems for these things, use your main system and if the character has a special scene that relies on a fetish, allow that character to perform special actions or enter special stances. If they no longer have that fetish, then just don't activate those special actions/stances. For an example Lilaya will remind you not to cum inside when your arousal is high, and can end the scene early if you do. But its the normal framework, the game just checks for those things inside the framework.
I wouldn't really ask inno work on changing any of this at this time though, cause it'll likely be a year before even half of it is done and what's there will be broken. I think people are getting tired of the whole reworked a system, reworked the rework of my system that inno has been doing.