Again with Patreon here, Patreon there...
Many games are on Patreon, games with incestuous content because the developers use other methods, for example a patch, a dialog box that allows changing the type of relationship between the protagonists and the Mc, without forgetting that they can post a slightly edited version somewhere other than Patreon (usually a simple story arc is enough). One patch and you're done. In fact, the choice of content belongs to the developers and not to Patreon or other gas plants. If you decide to do something forbidden, you're not going to do it under the nose of a cop, are you? (or your head has no electricity on all floors). This site (F95zone) is full of games and comics that have content way above the red line and if you allowed yourself to do even a tenth of what a Mc does in those games, you would leave a legacy of 2000 years in prison on Mars. I don't know where this version of SB is from, but the content is about "incest on". The sister, the twins, so if Dot decides to create other blood ties, I don't see the problem. It's him in the end who will decide, or maybe he has already made his choice