The Pit of Despair has also been done:
Pit of Despair (By MunstahMummah)
Fluffy Hell: Envy by FlameAres/LemonCurds
I’m interested in your take on the experiment, particularly with the pre-programmed behaviour angle and whether that makes your fluffies actual living things that have been cruelly labelled as a product, or just a biological furby incapable of a real emotional response.