As far as I know, the Mac Informer client delivers updates based on the installed applications. Right now, there is no selective update feature available which means that the client will offer the latest version of the software installed in your Mac. This is a great idea and you can forward it to the developers using the form on the Feedback page. Access the page and explain this feature to them. I guess it will be received well. While you are on the page, choose Suggest a feature from the Categories drop down menu.
Make sure to use a valid email address to receive responses.