This is a followup from.
The docs for template_preprocess_views_ui_display_tab_setting() say this:
+ * - defaulted: A boolean indicating the setting is in it's default state. + * - overridden: A boolean indicating the setting has been overridden from + * the default.
Which implies that these two variables are just logical opposites of each other, ie. defaulted = !overridden. Either the docs are wrong/misleading or we don't need to set both of these variables.
However, this task should be postponed on.