Selecting the active connection should disconnect and reconnect to it
Often when a network connection is unstable, I want to "refresh" it. With a different similar system I used, clicking on the active connection would disconnect and then reconnect it. This was very handy. I have used it the most when a wifi network has multiple connection points with the same SSID, and you move between them, but the system doesn't properly connect to the now-stronger signal.
If a patch to add this would be accepted, I might try to put one together. I'm new to the code, but based on a quick look, it seems that possibly
applet_menu_item_activate in applet.c would be the right place to insert the disconnect.