I agree especially with Tiffany if they are related her hesitations and Valerie teasing/pushing her towards MC makes logical in universe sense whereas a landlandy makes very little sense and the friend of his landlandy (Valiere) flirting somehow being scandalous at all makes negative sense. Jenny being your landladies sister also removes every reason not to pursue her beyond "no sex in 99 pls mc" which is more Scarlett/April's thing in the patched version
I am pretty sure when the game came out the rules/enforcement for incest were waaaaaaay more lax on Pateron, and i agree that the whole time travel plot where multiple girls have "missing" dads and MC just so happens to be having sex with their moms in the past fits pretty much perfectly
but in a practical sense its not really an argument as long as he wants to be monetized no siblings/parents/cousins/any blood relation are allowed any sort of sexual content at all so for example making a scene with a threesome between MC x Scarlett x April would be a waste and would make sense to not develop/render at all, I think the more interesting thing is if devs have gotten fucked over JUST and ONLY an unofficial patch what is going to happen when MC has sex with Tiffany? Is the multimod going to drop the incest part? Will it be removed from OP even if its pointless now? Will Jestur avoid that scene alltogether (please god no) because at one point you could play the game with incest?
Edit: I was involved in the initial discussions about skylar and the tats/what they mean for her and the story and I have no desire to dive back into what was at the time at least was a hot topic

I just thought it would be funny to see how her mom reacted to her getting two full sleeves and or being gone when she freaked out and triedto forbid her adult daughter from seeing her friend without a valid reason haha