This has been answered many times in the past. Having a futa toggle would be more than a whole content patch of work and outside of the developers intention.
First there is all the CGs that would need to be edited (this is about 30 minutes work each, then times that by 100+), then there is the toggle option which would take time to code and all the potential bugs that could introduce. Finally and most importantly the narrative of substantial parts of the game would need to be completely rewritten.
Your only hope for this is a community mod, I believe someone started work on a Phoenix one but not sure they continued it. Best place to ask about these are on the Discord.