Have you read Venusian Lullaby? It's a First Doctor, Ian and Barbara story with fascinating worldbuilding. The Venusians themselves reproduce as aquatic larvae -- budding, they call it -- and eat the brain matter of their dead at funerals to take on their memories. The biological and the social.
Yeah, it would be fascinating! Why does it feel so deeply unsettling...? I've no idea why that's the case. It doesn't appear to be based in social conditioning. Is the reasoning part of human intelligence based more deeply in the survival instinct than we give it credit for? It opens up a heap of deeply interesting ideas.
Nah, I have not read that one. Interesting. Sounds a bit like the very early Warhammer 40k concept of the Space Marines eating the brains of friends and foe to learn from the memories of the dead. Great concept in the early novel "Space Marine" by Ian Watson. Early Warhammer lore was so much more visceral that the smoothed out main stream version of today.
But is it social conditioning?
What if it is something encoded in our DNA?
What is it a creator did not want us to see or do?
There is tons of material for really awesome fiction.