It is a good idea to split your script into multiple files

• When writing scripts for bigger modpacks, your script might soon become pretty long and confusing.
• Debugging a long script might take really long, especially if you have an error that doesn't point out a specific line in your script.

• CraftTweaker can load files from multiple script files.
• CraftTweaker can even load files in subfolders.
• Also, CraftTweaker can load .zip files that contain .zs scripts inside them, as long as the .zip file is not password protected.

• Split your large scripts into multiple smaller ones.
• You could for example create one script for each mod, or each mod handler.

ZenScript
 Copy
scripts
    thermalExpansion
        Compactor.zs
        Crucible.zs
    Vanilla
        Recipes
            Remove.zs
            Shaped.zs
            Shapeless.zs
        Seeds.zs
    oreDict.zs

• Your script files become easier to debug.
• An error won't stop your whole script from working but instead only a small part of it.
• People checking your script files can easier orient themselves

• You need to be careful with the loading order of the scripts (especially if one script removes a recipe and another one adds it). Check the Priority Preprocessor if your script loading order is a problem
• There are many ways to categorize your scripts after and yours may be confusing for outsiders.