Bedrock Edition:Incompatible Mace Enchantments
Currently, Density, Breach, Smite, and Bane of Arthropods are mutually exclusive enchantments for the mace. However, only Bane of Arthropods and Smite were incompatible when maces were first introduced. Therefore, many incompatible enchantments were obtainable prior to this change.
Obtaining
While these enchantments were not mutually exclusive, they could be applied to the same mace or enchanted book using an anvil or an enchantment table. There are many possible orders and levels of enchantments and the other enchantments: Wind Burst, Fire Aspect, Unbreaking, Mending, and Curse of Vanishing can also be applied.
From Preview 1.21.0.21, when the Breach and Density enchantments were added, to Preview 1.21.0.23, the Breach and Density enchantments were not incompatible with each other. Breach and Density were also compatible with Bane of Arthropods or Smite. They were all made incompatible in Preview 1.21.0.24. These compatibilities made it possible to get a mace or enchanted book with Breach, Density, and Smite or Breach, Density, and Bane of Arthropods.