Well, anything that goes against Patreon's policy is instantly out of the question, so we'll NEVER do any incest, non-consual sex or underage characters, but that was probably obvious.
Other than that... Hard to say really.
For example, we never did any pregnancy, because we haven't found a way to properly implement it into the current story, but the kink itself is not something we're opposed to.
Honestly, there is nothing interesting or unique in our NOT TO DO list, since we just exclude the usual suspects: scat, guro or weird stuff like nipple-fucking.
But feel free to ask about the specific fetishes, because that would be much easier to answer!