Inconsistent omi field names compared to oemetadata spec

I used omi and when I output each field, the order is not the same as in the schema and there is a difference between the namings. Furthermore, there are also more fields displayed in omi than in the schema.

Here is a list of what I found:
General Keys:

• ID = identifier
• language = languages
• publicationDate = publication_date
• context
  • sourceCode = source_code
  • grantNo = grant_number
  • fundingAgency = funding_agency
    Spatial and Temporal Keys
• referenceDate = reference_date
• timeseries = timeseries_collection
  • start = ts_start
  • end = ts_end
  • resolution = ts_resolution
  • alignment = ts_orientation
  • aggregationType = aggregation
    Source Keys
• sources, licenses (In omi.licenses but not in schema)
  • identifier = title
  • other_references
  • text
  • comment
    Contributor Keys
• title = name
  Resource Keys
• All resources are shown with all keys and values at the end which shouldn't happen

There is also a problem that omi only outputs fields with values, if values = null --> these are not shown