[PatrickHenry]

The only thing we require to preserve causality is that no one at a given reference frame receives a message cognizant of a previous point in time in that recipient's reference frame.

That is precisely the problem that will arise, I believe. I pointed this out in post 119. One of us is seriously wrong about this.

[AntiGuv]

But your post 119 treats the exchange as if you have this:

Earth ---------------------> Starship

Earth <--------------------- Starship

That formulation is behaving as if there were two one-way communication channels with each one originating in the reference frame of its transmitter and then received in the reference frame of its recipient.

Unless I'm dreadfully wrong, the way to conceptualize our ansible is thus:

Earth <---------------------> Starship

You only have one two-way communication channel that is fixed in one inertial frame which happens to coincide with the Earth's reference frame even when transmitting from the starship's reference frame. This is because the entangled quantum on the starship that is interacting with the entangled quantum back on Earth remains on the same inertial frame.

Thus, a semi-permanent wormhole would present a problem for special relativity not only because it would breach the light-speed barrier but also because the reference-frame symmetry would be broken.

You are preserving the reference-frame symmetry, but the reference-frame symmetry is broken!!