Installation Question

Hello I’m looking at installing the Interface Kit into my Vista 10 panel. Does the keyswitch output have to be connected to a Wired zone? Mine are full, so I assume I can delete that zone in installer mode *56, then install a new wireless 5816 transmitter on the currently-wired window, before using the wired spot for the new Konnected board? Or should I upgrade to a Vista 20p main panel first?