Add a note into the admin screen explaining that you can use wiki markup and even an include macro to put an actual page onto the dashboard.

Also link to a documentation page on CAC that shows the value of doings so. The reason is that many of our customers don't even consider this option at all, don't change the welcome screen, or of so then in a dull way. "Welcome to the BigCorp dashboard" just doesn't cut it. We need to explain how we use this on out intranet.