[8.0] [product_attribute_types] domain on default and attribute values missing

[roedeorm]

The field default in attribute values seams to lack a domain.

Go to Sales>Product Categories & Attributes>Attribute line values
In field "Default", attribute values from ALL attributes can be selected and saved, not only from the attribute in question.

Similarly, and in the same view, in field "Product Attribute Value", when clicking on "Add an item", attribute values from ALL attributes can be selected and saved.

In consequence, I can add "Colour: red" to the attribute "Memory" of for example Product Template "iPad Retina Display" and also set the default of "Memory" to "Colour: red". That doesn't make sense.

P.S.: I can't find any effect of setting a default attribute value. When adding the product template to a sale order line or to a manufactoring order, the attribute with a default remains empty. Shouldn't that autopopulate with the default? Or am I missunderstanding the purpose of attribute value default?