JPA metamodel and @Convert on a List attribute

Question

I'm exploring the possibilities of using the JPA metamodel with the Criteria API.

I have some entities that have attributes like this:

@Column( name = "defaultValue" )
@Convert( converter = StringListToStringConverter.class )
private List<String> defaultValue;

The DB column is a VARCHAR that holds a comma-separated list of strings (it's a legacy table). The converter nicely allows to use a real collection type when working with this entity attribute. But I'm confused by the metamodel that EclipseLink creates. The attribute is represented like this:

 public static volatile SingularAttribute<MyEntity, List> defaultValue;

1. The raw type warning this declaration triggers is a little ugly. Is this enforced by the specification? Is there anything that would prevent the declaration to be this instead:

   public static volatile SingularAttribute<MyEntity, List<String>> defaultValue;
   

2. I wonder if this declaration can lead to problems when I construct Criteria queries based on this metamodel. For example, would it be possible to construct a filter that checks if some specific value is contained in the list, something like

   [...] where( literal( "element" ).in( entity.get( defaultValue ) ) )
   

   (maybe this makes no sense at all - I've really just started with the Criteria API basics)

3. Am I right to assume that a ListAttribute was not selected as the type for the metamodel here because the CollectionAttributes in general are only used for expressing relationships with other entities/element collections?