[duskwuff]

> If a client runs a Lua script, why can’t we just run it on their machine and propagate any game state changes (if the script adds an inserted, for example,) as if the player made those changes themselves?

The game already has to run Lua scripts as part of the simulation, potentially as part of in-game events which aren't directly triggered by players. A player running a script from the console is handled by that same interpreter -- making it run in a completely different operating mode where any changes to game state are replicated would be much more complicated and prone to error.

Or, from the other direction: the game's multiplayer model is all based around a replicated simulation where player inputs are fed into the simulation. Treating a player running a script as a special kind of event involving the text of that script is the simplest and most obviously correct way to implement that.