We'd like to use a Singleton to control capabilities of an entity set, e.g. use a property of a singleton to tell whether the authenticated user is allowed to create new entities in a given entity set. This means we'd like to use a Path construct for the value of @Capabilities.InsertRestrictions/Insertable, e.g.

<Annotations Target="My.Container/SalesOrders">
<Annotation Term="Capabilities.InsertRestrictions">
<Record>
<PropertyValue Property="Insertable" Path="/My.Container/Me/Permissions/CanCreateOrders" />
</Record>
</Annotation>
</Annotations>