bOverrideAccessibleDefaults

These editor-only properties exist for two reasons:

To make details customization easier to write, specifically in regards to the binding extension widget

To allow subclasses to set their default values without having to subclass USlateAccessibleWidgetData Every time one of these properties changes, it's data is propagated to AccessibleWidgetData if it exists. The creations of AccessibleWidgetData is controlled by the details customization through a CheckBox. The reason this is set up like this is to reduce the memory footprint of UWidget since overriding the default accessibility rules for a particular widget will be relatively rare. In a shipped game, if no custom rules are defined, there will only be the memory cost of the UObject pointer.

IMPORTANT: Any user-editable variables added to USlateAccessibleWidgetData should be duplicated here as well. Additionally, its edit condition must be manually assigned in UMGDetailCustomizations. Override all of the default accessibility behavior and text for this widget.