in document type editor, selecting the "Canonized" mixing does not reset properties

• open CMS
• in browse perspective, in configuration, in hippogogreen namespace, open the "address" type
• click edit
• select "street"
• open mixins
• select "Canonized"

The properties for "street" remain visible, it would be better to clear those, perhaps also display a message that "Canonized" cannot be added as an editable property