I updated Microworld mod from Stonehearth dev team to include a new world : Building Editor.
This allow players to build freely with all furnitures available in the custom build tool (every crafter is present and max level).
You will be able to build anything in a flat world without having to start a new game or go through the rooster and map selection.
To launch the mod use this command :
Stonehearth.exe --game.main_mod=microworld --mods.microworld.world=building_editor
Also, make sure you launch the game at least once to have saved_objects folder created before designing templates using the building_editor microworld.
Installation guide on Youtube : Stonehearth - Microworld mod - Building Editor
Mod link :
Let me know what you think !