preview page model API does not show preview hst configuration

When using the PMA with a mobile app, it makes sense to connect the app to an external preview mount to be able to preview the content and hst configuration changes before they are published.

When a mount type=preview is added with the pagemodelapi=resourceapi, the unpublished content is shown as expected but the unpublished configuration changes are not.

Reproduction

1. Create archetpye project
2. Convert to enterprise
3. install news
4. Add hst:pagemodelapi=resourceapi to /hst:myproject/hst:hosts/dev-localhost/localhost/hst:root
5. Add a mount 'preview' below this node with hst:pagemodelapi=resourceapi and hst:type=preview
6. Log into the CMS and go to the Experience Manager
7. Add a news list to the container of the homepage
8. Change the title of a news document

Expected:

1. The changed title is visible in http://localhost:8080/site/news/preview/resourceapi, but not in http://localhost:8080/site/news/resourceapi
2. The news list is visible in http://localhost:8080/site/preview/resourceapi, but not in http://localhost:8080/site/resourceapi

Observed:

1. The changed title is visible in http://localhost:8080/site/news/preview/resourceapi, but not in http://localhost:8080/site/news/resourceapi

2. The newslist is not visible in http://localhost:8080/site/news/preview/resourceapi or in http://localhost:8080/site/news/resourceapi