De-Dupe / Return Draft DjangoCMS Plugin Instances

admin.py

def formfield_for_foreignkey(self, db_field, request, **kwargs):
        if db_field.name == "my_plugin_fk":
            kwargs["queryset"] = models.MyPluginModel.objects.filter(
                Q(placeholder__static_draft__isnull=False) |
                Q(placeholder__page__publisher_is_draft=True)
            )

        return super().formfield_for_foreignkey(db_field, request, **kwargs)

See:
https://stackoverflow.com/a/30384714/1082663