I'd like a mod that expands the body decomposition feature, wherein there is only a certain chance of human corpses "being cleaned up" (disappearing) that scales with their proximity to the nearest town instead of them always disappearing if near roads. Maybe even go farther and make an optional feature of NPCs actually having to pick up corpses and taking them to an Undertaker/Doctor's shop in a nearby town to get rid of them, or allowing NPCs or even the player to bury corpses out in the wilds. Other than that they would stay until the final skeletal decomposition stage. I imagine this will be resource intensive, especially if it'll include mission NPC corpses, which i think should also be an optional feature for people with good enough computers.