[Practicality]

Cornell seems to like putting out phd theses on this subject:

https://arxiv.org/abs/1607.07871 https://arxiv.org/abs/1608.01528 https://arxiv.org/abs/1607.00381 https://arxiv.org/abs/1605.06022

Seems like Cornell is wasting a lot of time researching something that you've already determined is impossible.

[jessriedel]

Everything you're linking too is either highly speculative (e.g, hypothetically taking place yoctoseconds after the big bang, and completely unconfirmed) or is addressing some subtle interpretative senses of causality which are very distinct from the normal sense (such as the paper by Leifer and Pusey, who worked/work down the hall from me).