Build has some protective regions and the ability to rollback grief with the history plugin but it is rarely griefed due to the requirement of crew in order to do anything outside the sandbox. Surface is left mostly unprotected so anyone can add their teleporters there. Not sure why you would still think it was protected if destroying the tiles actually dropped items or that the purpose of the dimension is for free building.
Dimensions such as rift, items, gamemodes, and specialitems are tsl servers (terraria server lite) that have just enough functionality for players to join and do some things on like getting free items or for use as a hub server. It just repeatedly resends a small chunk of a world schematic file and simply cannot be edited ingame. Build is a tshock server with less protection than most servers as the requirement of crew drastically reduces the number of bad actors, as most don’t have the effort to verify or don’t actually own the game.
Can you recite to me what griefing is in the rules?