aggregate report requires to have aggregate=true configuration parameter

Project setup: I have a multi-module project (standard nested layout). The reports are configured in the parent project. I use the "aggregate" report to create an aggregated javadoc by the maven-javadoc-plugin:
<reportSets>
<reportSet>
<reports>
<report>aggregate</report>
<reports>
</reportSet>
</reportSets>

Problem: The aggregate report is ignored, when I launch the "mvn site" command, unless the aggregated parameter is set to true in the maven-javadoc-plugin configuration. So the following setup is required in pom.xml:
<reportSets>
<reportSet>
<configuration>
<encoding>UTF-8</encoding>
<aggregate>true</aggregate>
</configuration>
<reports>
<report>aggregate</report>
<reports>
</reportSet>
</reportSets>

Desired functionality: Launch the aggregate goal, if it is declared in the report section. Do not require the aggregate parameter=true setting (it is a duplication and also the aggregate parameter is deprecated). The following setup should be enough in pom.xml:
<reportSets>
<reportSet>
<configuration>
<encoding>UTF-8</encoding>
</configuration>
<reports>
<report>aggregate</report>
<reports>
</reportSet>
</reportSets>

Comment:
The aggregate goal works fine (it does not require to have the aggregate=true parameter), if it is launched directly. That is by the "mvn javadoc:aggregate" command.
It just does not work, when it is launched indirectly through the site plugin as a report.