I don't know if the client makes any distinction between them and any other door on a map, but if it's possible to distinguish someone interacting with a transport object (i.e., portals, ferries, trams), would it be possible to make doing that bring up the mapmenu for zone selection? Because you'd be able to go anywhere from a portal, tram, or ferry, it wouldn't be an accurate recreation, but it would give a little more feel of things working again.