The doclet parameter will generate the documentation using the specified doclet. See the Doclet Overview for details on how to create a doclet.
<project>
...
<reporting>
<plugins>
<plugin>
<groupId>net.sf.jfxdplugin</groupId>
<artifactId>maven-javafxdoc-plugin</artifactId>
<version>1.0</version>
<configuration>
<doclet>org.myorg.doclet.MyDoclet</doclet>
<docletPath>${project.build.sourceDirectory}</docletPath>
</configuration>
</plugin>
</plugins>
...
</reporting>
...
</project>