Should output serialization properties be added to pipeline outputs?

[ndw]

Consider this pipeline:

<p:declare-step xmlns:p="http://www.w3.org/ns/xproc"
                xmlns:cx="http://xmlcalabash.com/ns/extensions"
                xmlns:xs="http://www.w3.org/2001/XMLSchema" 
                xmlns:s="http://example.com/ns/steps"
                name="main" version="3.1"
                exclude-inline-prefixes="#all">
  <p:output port="result"/>

  <p:declare-step type="s:inner-step">
    <p:output port="result" serialization="map{'indent':true()}"/>
    <p:identity>
      <p:with-input><a><b><c/></b></a></p:with-input>
    </p:identity>
  </p:declare-step>

  <s:inner-step/>
    
</p:declare-step>

The output of this pipeline is not indented.

If s:inner-step was an XSLT step and it specified serialization properties for the output, those would be preserved in the document properties and the result would be indented.

That discrepancy strikes me as kind of odd...