I'm thinking this could be a way to copy chiseled blocks in survival. You could shift right click on a chiseled block with clay in your hand to make a mold of it that can then be fired and have molten metal poured into it to create a copy when it's cooled down. This could be useful to mass produce smaller designs but also for larger multi block statues. You could copy each block and then infinitely copy the pieces with metal to be assembled later.