Is it possible to use DUPLO bricks in LDD? Is there a way to import DUPLO bricks to Lego Digital Designer? Or is there another way to make DUPLO build instructions?
LDD is a closed world where people can't add its own parts. If you want to create Duplo building instructions you should use LDraw that has many Duplo parts in its library, and allows you to create the missing ones if needed.