Scott, thanks for the offer. The user interface is virtually complete, unless I find bugs or need to tweak features as a result of trying to create the feed.
The user interface does change if you are registered. To see what changes, log in here:
http://potomactavern.org/phpBB3
Use this User Name: Smartfeed Tester
Use this Password: smartfeed
You should see forums that cannot be read by non-members.
Select the Smartfeed icon near the top right.
Note that when logged in you see "Show only your subscribed topics in the feed?" If you say yes, the New Topics control is disabled along with the forums, since logically they should be disabled.
Now, as for the program that generates the feed itself (smartfeed.php), I haven't started that. As I said, it will have to be rewritten. That will be a long process, unfortunately, because it is much harder than the user interface. I will start simple with text only newsfeeds and slowly build it up.