Proposal for issue 9607 (http://tracker.modx.com/issues/9607)

You should be able to hook multiple plugins on `OnBeforeConfigSet` event and either output a key or an array of keys to be unset : 

```php
$modx->event->_output = array('access_resource_group_enabled', 'access_category_enabled');
return true;
```
or

```php
$modx->event->output('access_resource_group_enabled');
return true;
```