The plugin indicating it's bindings is the *only* thing to do here.
Otherwise, the host can just bind however it wants.

It is a simple idea much older than that thread, just nobody has done it
yet.  Doing it statically is trivial: just set properties on ports to
indicate their binding.

Absolutely. This is exactly what I'd like to do.  Is there a reason we shouldn't implement this before we figure out the more complicated scenarios?

Jeremy