I actually think both fit the game. I played without the patch and I liked it quite a bit that way
Forgive my ignorance, But the MC's mom is dead. And there is no mention of a sibling.
So without spoiling, how does the incest fit in the game?
Confirming that it fits in neatly will be enough for me if you can not provide an answer without spoiling it.
I always try to play a game as the dev intends it to be (If it were not for Patreon). I hate Landlady, Best friend from Childhood (Staying in your house) and other contrived type of shit. But the incest should provide some plot point or social taboo.
There is no stigma/plot point IMO in fucking your Landlady or some chilhdood friend that happens to stay in the same house.