SpacesEngine already gives individual Spaces owners the ability to turn off Tabs and Buttons in their Spaces profile under each Spaces' individual Settings tab. But why not give the Admin the same ability to turn off or hide tabs and buttons globally for all Spaces? That way, if there is a tab or button that is not necessary for a particular use case, the owner of the site can simply turn it off and it will not appear anywhere in the Spaces pages for any user. Those controls could appear in the main settings area on the WordPress backend.