Content Search - Some properties are not being exported

Hey,

I have noticed that some document properties are not being exported into the content feed. My understanding of the exporter is that all properties by default are all exported.

One of NHSD most important document types is 'Legacy Publication'. I've attached a sample legacy_publication.zip and the Exporter_Output.json for the specified document.

The following fields are missing from the output:

common:FacetType String

common:orderedSearchDate Long

common:searchRank Long

publicationsystem:PubliclyAccessible Boolean

 
We need some of these fields for search results rendering namely (common:FacetType & publicationsystem:PubliclyAccessible)

Could this be investigated please? 
It's possible to reproduce through NHSD project branch: DW-1544-content-search :https://github.com/NHS-digital-website/hippo/tree/DW-1544-content-search  

Please let me know if you require more information.

Thanks
Shane