In that thread, have a look at the "Bridge" chip, and how I've wired that up to two buses. It's verbose, but it works.
To your point, being able to link bridges without a chip would be nice, but this does, at least ,work for now.
The problem with this method is that even when both inputs are offline, the bus wires retain some 'memory'. It's some progress, but it's not ideal.
That's gotta be a bug.
I will try to reproduce :)
