On the same topic, I've whipped up this mod before going away, and decoupled it from my other code today. Check it out, see if it's worth pursuing.
What it does is to set up a "mass grave" location. NPCs will randomly and automatically pick up dead bodies, carry them to the mass grave site, and dump them there.
You can also use NUM6 (not F6) while focusing on a live NPC to make it stop whatever it's doing, pick up the nearest corpse and carry it to the site.
So far there is only one site configured, in Valentine, the pig farm behind the sheriff's office. If this mod gets traction, and if I have the time, I can (probably, no idea how, but can probably figure it out) add a dynamic list of sites that we can crowdsource the coordinates for.
Please note that the mod will generate an ever-growing (although slowly) log file. Please delete manually if it gets too large.
Also, please report here if you notice any of the bugs described in this file comment. I am running a lot of personal code and I have been trying for a month to track down that issue, still can't figure it out.
Also, please report if you get occasional stuttering. In my testing I haven't had any significant performance issues, but it helps keeping an eye out.
SAC dead body removal.asi
SAC_dead_body_removal.ini