I think I may have a possible solution so long as the unit is civilian or alien, it won't work for a X-Com unit as the player could remove the required item from their inventory.
If an auto-primed grenade is placed in the units backpack with RadiusReduction: 100.0 and damageAlter: setup to only provide damage via ToItem: in theory the grenade will clean up the invisible corpse so long as the blast exceeds the corpse item's armor: value.
The negative of this approach that I can see is that the player's camera will snap to that location briefly when the grenade explodes which could accidentally trick the player into thinking there is alien activity in that section of the map.
I haven't tried it yet, but I think it could work.
I already said it's not feasible to use the current overkill feature for your use case.
Don't know what else do you expect me to say...
I was hoping that your previous message was only covering the changes possible via the existing .rul yaml variables and not the advanced scripting.
Thank you for confirming that there is no script command to trigger the Overkill state on demand, that saves me a lot of trial and error.
Right now most of scripts are caped on 0 when you can current health, one way as hack is set `overKill` in armor to negative value, but this will have side effect like items in inventory start getting damage when your hp is very low and game start consider it "overkill".
If I set the equipment carried by the unit to have an unusually high armor: value would that negate the problem with a negative Overkill value on the armor setting destroying the units equipment?
Additional question: can Overkill be triggered by a death caused by fatal wounds or negative health recovery on the unit's armor or is an Overkill only able to occur from direct weapon damage?