Long ago when versions of remote desktop changes the /console switch to login to the console of a server remotely stopped working, some time around the release of the OS that shall not be named by Microsoft. (Vista).
Anyway, I just did some digging and found all these incorrect solutions, so here it is.
As tested on version 6.0.6001.18000 of remote desktop
/console has changed to /admin
works just as before.