I don't think they know what they're talking about. Everyone these days seems to make the default version of these games have relationships like landlady and roommate and then just have a simple one-file-patch.rpy that makes it a wincest version distributed outside of Patreon.
But as for the blackmail stuff, I think that's unlikely to fly on Patreon too. I don't know what the rules are on SubscribeStar, though
I do see a lot of people complaining about no animations or poor animations. Having music and sound effects also goes a long way to raise production value.
It's a lot to handle, but overall I think you do want to balance a few things and make sure you're mostly equally good on all of them: plot, characterization, pacing, lewds, animation, limited grinding, sfx, music, frequent communication, twice annual updates, and a bug free experience. I think that's the expectation in 2024
Good luck!