I'm not sure this would be possible, but the idea just popped into my mind. In other games you can put custom scripts into a folder and load the mod from an in-game menu.
I'm not sure if a compiled 3DGS exe is able to load and run any form of external non-compiled code, but it would be great if it could.
Does anyone know if there is any way this is possible? (Or is anyone sure this is impossible)