Lua allows modders to overwrite the vanilla version of the game's files through its loading order, as you touch on. The code doesn't actually change that much (I think the last major one that broke a mod was two years ago when the scavenge table was removed from item distribution.) It's more so that some mods have always been broken and the mod owner either isn't around or interested in fixing it. Sometimes they might not be aware of it or be the creator of that code.
Since so much has changed over the years and mods become outdated since the coders are updating and changing things all the time to fix and improve the game you think maybe that an API type for modders might be created and you can update the API without changing how mods hook in?
As a layman would this simplify things for both sides? Or do the mods try to overwrite the vanilla with their calls and this is where the errors tend to come in?
So far was not able to reproduce the death from overweight.