This plugin adds the ability to lock/unlock switches with the presence of a file in a /dlc/ folder. This is a comically basic implementation of DLC, in that every user will have access to the DLC files in their games, but all locked away content should only be accessible if they have a certain file in the /dlc/ folder (or if that switch is flipped via other means). This way, when you want to add extra content, such as DLC, people won't have to download a custom build of your game.
Note that this plugin was made for internal use and might be very finicky to work with. Remember to read the documentation, enable console output by uncommenting the lines, and checking that it works. It assumes the presence of a /dlc/debug.txt file to switch switch 100 to true on. I use a Common Event that calls the script DLC_Check() to make it work, and have that be called in parallel if it's a map that requires it.