Place in the world settings an option to warn the server when a player hammers or burns a building made by players, Alchemy, Ice Flingomatic, Crockpot, Chests, etc.
This is an option, can be enabled or disabled in the settings of the world
If possible, you can also add a drop and health balance option, damage the bosses according to the number of players.
Example: 50% more life per player
It can be activated or deactivated in the creation of the world.