The debug parameter will generate the javafxdoc.bat (or .sh) execution script along with the options and files files that are used to generate the documentation.
<project>
...
<reporting>
<plugins>
<plugin>
<groupId>net.sf.jfxdplugin</groupId>
<artifactId>maven-javafxdoc-plugin</artifactId>
<version>1.0</version>
<configuration>
<debug>true</debug>
</configuration>
</plugin>
</plugins>
...
</reporting>
...
</project>