If the rooms are kinda decorative yet also serve a purpose it could be a place to store and display your Redstone stuff, also maybe have little systems in it
need ideas for the final room in my mfc base. have to have to seperate areas with something in each. must be purely functional for survival mode. cant be a nether portal, bed area, worktables, smelter, storage, armor/tools, or potions, as i already have those