[Kaelon]

Adsense for Feeds is misleading. What it requires you to do is feed your feeds through Feedburner, a service that Google purchased. Then when users review feeds on the web, they are displayed Adsense ads. So you have to manually create each and every feed on Feedburner, and then re-direct your website's reader traffic to the Feedburner page to display your feeds with Adsense in-line.

It's just not feasible for how external.php works, which generates feeds dynamically based upon your forums. So unless you have very static forums (that won't change their layout, names, configuration, numbers, etc.), then this won't really work for active vB communities.