Feature Request: Per-class and/or per-folder notification options?

I would like to be able to control notification options on a per-class basis (different notification sounds per class, etc). Right now, you can only select one set of notification options and whether or not that set of notifications is triggered by a given class.

My use case is that I'd like my 1st class folders to make a sound, but my 2nd class folders to trigger a notification in the status bar without making a sound (the idea being that my 1st class folders are important enough that they should be able to tell me to look at my phone if I'm not looking at it, the 2nd class folders are important enough to tell me to look at my mail client only if I'm already looking at my phone).

This is not a bug request so I dropped the template, hopefully that's not a big issue.

The issue names no files, tests, or entry points. Start by locating the existing notification settings and how class or folder rules trigger notifications; done means users can configure distinct notification behavior, such as sound versus status-bar-only alerts, for different classes or folders.