Seeing that there's not much support on the patreon, it must mean the ntr fans aren't really that many. It's difficult to balance between ntr path and non ntr paths. The harem/vanilla crowd filter out games that even mention ntr in them, so you already lose a massive chunk, and since ntr is niche, relying on only that small crowd is quite challenging if there's no support.
If people were serious about wanting ntr content, support the dev so you can get more of that. Seems like it's a waste of time and resources to focus on 2 paths for the dev, hence why they dropped ntr.