Hello,
"I think you are getting emails even though Notification type = "Notification" because in Project Scoping you might have selected Business Task Management to be notified with different notification channel i.e. email.
Uncheck the scoping question, as these task would be anyway raised as Notification. So you will have only Notifications in C4C."
I agree with that statement
"My understanding was that it Business Task Management is not related to the workflow rules - but layout of the email is similar to the ones sent regarding incidents so you may be right."
Even if it is not directly related, when this option is activated in scoping, you will receive an email for every notification you get in the system.
If you uncheck this option, your workflow will only send a notification.
Best regards,
Benjamin