I think it would be useful for sub-account users to be able to change the due date for a shared course. Each sub-account represents a different client in my use case, and each one has different due dates. It would be easier for an admin in each account to change their own due date, instead of notifying me to change it for them.
Copying the course each time I have a new sub-account is a bit of a hassle, and it creates a new course in my root account as well. I'd rather just share the course and let them change the setting.
This is similar to how the Certificate and Open Book option can now be unique across sub-accounts with the last update.