This, with apologies, is a short posting that may lead to a lot of work.
Copying in the early years of secondary school is concentrated in the following areas
Copying out "learning objectives"
Copying chunks of writing frames
Gap filling exercises which involve copying either the answers or the whole text
Comprehension exercises that can be answered by copying sections of the original text
If they can, some children will copy, however much we ask them, or tell them, not to.
If the basic case is accepted, that the jerking backwards and forwards involved in copying interferes with the development of networks in the brain, and hence of children's powers of personal expression, there is only one solution:
1 Identify the tasks that involve copying, and pin down exactly where and how the copying takes place
2.Redesign the tasks so that they can't be completed by copying.
As I said, a lot of work. I'm happy to help anyone carry it out by email.