it would be cool to have a mod that allows you to convert rotten flesh to leather by putting it inside a furnace or smoker.

There is already a Vanilla Tweaks datapack for this: https://vanillatweaks.net/share#kjFFlG

There is already a Vanilla Tweaks datapack for this...

there are many mods and datapacks that do this, but i would prefer a serilum mod.