I have implemented this: when in an Agora subnode there is a block that begins with [[go]] and continues with a URL, the Agora will set up a [[go link]] with it and make it available at anagora.org/go/ + the node id. Example follows.
Note currently I also run go links on https://flancia.org , my personal domain, and they’re incomplete (they contain a subset of the go links in the Agora).
Next up: handle the case in which several subnodes set up different go links.
Behaviour now: one is picked opaquely; the username with the username that comes first alphabetically "wins".
Expected behaviour: perhaps a list with all targets shows up, and then five seconds later the Agora redirects to the most highly ranked target (to begin with, the oldest?).