Sometimes I need to adjust the volume of an app but it's not available because it's not currently playing audio. For example, I may start an app doing something, and when it's done it will make a notification sound, but then want to go to bed while it's running and not want it to make a (loud) sound when it's done while I'm in bed. This can't currently be done if the app isn't shown in BT (in the flyout). If there was an icon (usually a bullseye/crosshairs in other apps that have similar features) that could be dragged onto the program, it could be used to tell BT to add that program to the mixer/flyout, and then its volume could be adjusted. This could either be added to the tray icon's context menu or, ideally, to the flyout, or both.