Restrict creation and amendment of Nintex forms

In the previous version of Nintex you could restrict who could create and edit forms. In the new cloud based version anyone who is a site owner can do this. We have hundreds of Sharepoint sites and the people who they are created for are the owners. A number of them have created a large number of Nintex forms, which we are unable to prevent. We need to be able to stop people creating forms or amending forms and have only a select group who are able to do this. It's a nightmare with licensing and development standards.