Lockdown
Overview
Lockdown is a compact modification primarily intended for modpacks that utilize pre-made maps. This mod was originally developed for the FTB team for the Pax East event. Subsequently, the author received a recommendation to release the mod publicly due to the growing popularity of maps in the style of Agrarian Skies, where such functionality would prove quite useful.
Core Functionality
The key feature of Lockdown is creating exact copies of a specified template when generating new worlds. The path to the template folder can be configured in the configuration file (by default, .minecraft/template is used). The template format does not require special processing - simply copying or renaming any existing map is sufficient to create it. Using templates instead of standard world generation can be enabled or disabled in settings (by default, the feature is active).
Interface Simplification
The mod also allows hiding or disabling certain interface elements. The button for changing the world's game mode, the additional settings button, and the button for switching to multiplayer mode - all these elements can be configured or disabled (by default, they are deactivated).
Additional Resources
For additional information and discussions, there is a Discord server that can be joined using the invitation link: https://discord.gg/0loJvLMgvZi0q596
The author also maintains a Twitter account: https://twitter.com/TheAdubbz