krandrtray had ability to change resolution just via context menu of systray icon. This was very usable and _much_ faster than opening KCM window, setting resolution and then (if resolution is too small) dragging window offscreen to actually see ok/apply buttons... Please add ability to change resolutions by right-clicking kscreen icon in systray.
Everything else in the applet is currently global, rather than per-screen. But each screen has its own resolution, so we would need to add a screen chooser UI to the applet. I think this would be quite hard to stuff in there in a way that felt right. So I don't think we'll be able to do this, sorry!