Starting with the previous config, I change EtherTalk to “Nonseed” so it just becomes a client on my main network ("BaroNet”) that's already beeing seeded by Apple Internet Router. The config window still shows the "RefRouter EtherTalk" name but that whole section is actually disabled.
For LocalTalk, I’m now seeding a separate Zone with the name "BaroNet LocalTalk”
And now the RefRouter now sees all of #GlobalTalk on the nonseed port!