The "Monitoring" section in portal.properties provides valuable information for measuring the performance of portlets on the page.

As activating the properties in there also requires monitoring-spring.xml to be added to spring.configs, this should be mentioned in the comments in the monitoring section. Also, the text for monitoring.show.per.request.data.sample mentions that the information will be added to the end of the page - it would be helpful to mention that it will be added as HTML comment, so you can't see it in the browser, just in the sourcecode