Jason Cawley
Wolfram Science Group
Phoenix, AZ USA
Registered: Aug 2003
Posts: 712 
The conventional understanding has been that EPR rules out hidden variable theories, but that is not strictly correct, and it has been known for quite some time. What EPR shows is that you can't have a local, classical theory with hidden variables. You can get a consistent hidden variable theory if you drop locality, which e.g. David Bohm proposed.
More recently, David Deutsch has argued that you can keep local information and information transmission, as long as it isn't locally accessible (even in principle). Which is a relaxing of the amount of real nonlocality needed to get a hidden variable theory to work. (Deutsch is himself a manyworlds QM guy, instead, but wants the locally inaccessible information point for other, QC reasons).
But none of it is at the level of conducting experiments, and nobody involved disputes the standard results of two slit. Nor does anyone involved think subjective models are the way forward  amateur philosophers go for that angle, not physicists.
NKS argues for what is in effect a hidden variables theory, with some discrete and deterministic underlying structure of which QM is an emergent, large scale property or coarse approximation. Since it proposes that space as we experience it is an emergent property of its underlying network, it is not committed to locality in that emergent space as a basic feature. Wolfram discusses the subject in the notes to the final sections of chapter 9. He acknowledges that as yet no one has succeeded in making a discrete generator for QM work, but thinks he has sketched enough to show how it might be done.
The basis requirements of such a theory have been known for decades and are reasonably simple. Anything that gives appropriate brownian motion plus the right interference statistics at the microlevel, can give standard QM at a macrolevel. (All of QFT is a somewhat taller order it is true). Smolin and Hooft have both used that in the past.
Everyone should keep in mind that all of this is speculative stuff. Our best current physical theory is QFT and it is not discrete as math, and its usual interpretion is in terms of probability. A fair number of pretty bright people are looking at various different ways of changing one or the other of those things, but so far they have not successfully done so.
I hope this helps.
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