You can create a custom button that would call the action to add a row and then categorize at the same time.
You would have to customize the delete button, as well.
You can run the tracer tool to see what actions are called when you categorize and add.\/delete a row. This will give you insight into the rules being used. i would start with those rules and add them both to occur on an action if this poduced the desired behavior. Otherwise, I would use those as a starting point to explore what I need to modify.