Add a section, add a heading to the container, apply a class to the heading, lock the class.
Select the heading ID.
Now try and style the container or the element, all the settings are locked.
If you now go back to the heading and select the class and repeat the attempt to style the container or the element the settings are available.
So:
if a locked style is applied to an element, and deselected or removed, all parent elements are locked from setting adjustment, until you apply another locked class to the child and keep it selected.
Also if a locked class is added to an element and then deselected to add settings to the element via the ID, you can’t as the locked class locks all settings on the element.