arrokoth_porter_2024.lblx
- Suggestion: use Product_Observational instead of Product_Ancillary. 
The Information Model does say Product_Observational is "produced by an
observing system." However, I suggest that this is more like super-derived
data than like SPICE data. Also, the PSI shape models are (all, I think)
Product_Observational.  No complaints from here if you leave it.

collection.lblx
- Suggestion: in this file add the union of the children lid_references, i.e.
  urn:nasa:pds:context:instrument:nh.lorri
  urn:nasa:pds:context:instrument_host:spacecraft.nh
  urn:nasa:pds:context:investigation:mission.new_horizons_kem1
  urn:nasa:pds:context:investigation:mission.new_horizons_kem2
  urn:nasa:pds:context:target:trans-neptunian_object.486958_2014_mu69

overview.lblx
- Use https for NASA URLs, i.e. change
  <?xml-model href="http://pds.nasa.gov/pds4/pds/v1/PDS4_PDS_1J00.sch" ...
    xsi:schemaLocation="http://pds.nasa.gov/pds4/pds/v1 http://pds.nasa.gov/...
to
  <?xml-model href="https://pds.nasa.gov/pds4/pds/v1/PDS4_PDS_1J00.sch" ...
    xsi:schemaLocation="http://pds.nasa.gov/pds4/pds/v1 https://pds.nasa.gov/...