Options are very limited, really. The ones I've tried and somewhat comply are:
- Life Play: Very ugly, wonky, and abandoned, but you can inbreed all you want.
- Adam and Gaia: Listed in the OP. Html, text based with inconsistent pictures, and only F/D, F/GD, etc.
- Lab Rats 2: Listed in the OP. I think is the best of the lot. Has all the flavour text, decent gameplay loop, but your kids never grow so no F/D.
- The Sims 4 modded: Limitless possibilities, but you have to mod it a lot for it to look good and be fun and lacks a a lot of flavour text (I don't think there's a mod that adds incest situations) which means a lot has to come from your imagination, and it is expensive as fuck. Also, breaks more and more with each update.
Just my two cents.