And again, whether you use it or not...it hardly changes the 'whole story'...
I'm not against the mod but it does.
The canon story is mom dead years ago and Monica was her best friend. Not only does the mod change that it also puts in a ton of plot holes.
Why did the dad leave his daughters behind, why aren't they in the will. As his ex wife and mother of his kids, Monica would have the right to contest the will to a degree. She would certainly have the right to contest years of child support which would fix the issues with her business.
The we have the party with the whole revenge scene which was pretty much a love letter to Katie used to put down the other 2. In the mods case it's a public confession to his sister which would have been far more socially damaging to him and Katie than the 2 it was supposed to be.
I'm not against incest but not all games are fit for it and the canon version of this story is not suited for incest. That's why the mod is an entirely separate thing and Cheeky gets pissed when people review his game basing it on the mod.