According to the HAL specification, when fetching a list of resources, the response doesn't have to embed those resources in the response. Instead, it could provide a list of links for fetching each resource individually.
When fetching a list of resources, the current version of ngx-hal extracts the items from the response. If the resources are not present in the response, the library makes requests for those resources automatically. That automatic part should be refactored and made customizable.