On the Financial Management Defaults page there is an Access Rights section with a checkbox to enable or disable:
Grant Resource - Edit Financial instance right to resource managers
What does this option do? What is the functionality behind?
When a user is appointed as Resource Manager of a resource, an automatic right is granted: Resource - Manager (Auto)
If the Access Right option is enabled on the Financial Management Defaults, an additional instance level access right is granted: Resource - Edit Financial
If the option is disabled, the access right is not removed from the Resource Managers.
Those can have the same access right manually added and switching the option on and off will not have effects on editing or not editing resource financial details