Not all header items being added to multi-series SDMX output

[LucyGwilliamAdmin]

Some header items are missing from all.xml SDMX output - ID, Prepared and Sender.

See example below:

Also I'm not sure if Test should be true or false as in all.xml it's false, whilst in 1-1-1.xml, it's true. I'm thinking it should possibly be false?

all.xml (multi-series output) header:

<mes:Header>
  <mes:Test>false</mes:Test>
  <mes:Structure structureID="SDG">
    <com:Structure>
      <URN>urn:sdmx:org.sdmx.infomodel.datastructure.DataStructure=IAEG-SDGs:SDG(1.3)</URN>
    </com:Structure>
  </mes:Structure>
</mes:Header>

1-1-1.xml (single-series output) header:

<mes:Header>
  <mes:ID>IREF1616086814</mes:ID>
  <mes:Test>true</mes:Test>
  <mes:Prepared>2021-03-18T17:00:14</mes:Prepared>
  <mes:Sender id="uk_ons"/>
  <mes:Structure structureID="SDG" dimensionAtObservation="TIME_PERIOD">
    <com:Structure>
      <URN>urn:sdmx:org.sdmx.infomodel.datastructure.DataStructure=IAEG-SDGs:SDG(1.3)</URN>
    </com:Structure>
  </mes:Structure>
</mes:Header>