Eww. There might actually be a fair bit of work related to this. It looks to me like most damage dealt by mods don’t register a reason. I’m confronting this indirectly at the moment with bees. For the time being, bees are also going to damage armor. ☹️
There should probably be an ‘ignore_armor’ field recognized by 3d armor. Getting 3d armor to recognize it will be trivial, but finding all the many places where damage is dealt and adding appropriate flags may be a real bear.