Okay, I'm all for playing with the interpretation. Do we go after the popular quantum mechanical formulation of wave form collapse of an entangled partner happening as a result of an observation on the other partner or do we go after SR's interpretation of simultaneity? Both are discussed. And, both might lead to a proper interpretation in this instance (but, not necessarily a universal and problematic free interpretation for the theory in general). But, I have questions about what you offered as an explanation:
***The situation you just described appears to me to be essentially equivalent to the situation dealt with by Bell's Inequality.***
This thought experiment seems to me to be slightly a different focus. The Bell Inequalities are focused on causality of quantum events that are space-like separated whereas the focus of this thought experiment is simultaneity between frames that are space-like separated. If action-at-a-distance occurs between quantum entangled pairs, not only is SR's posit of faster than light communication in jeopardy, but so is the simultaneity of events in different frames that are space-like separated. I imagine that Barrett focused on simultaneity versus causality since SR could survive as unmodified if FTL speed communication was possible since the paradox could be explained by some bizarre wormhole geometry that quantum mechanics makes use of. However, the simultaneity of different frames would mean modifications to SR.
***These quantum mechanical quirks are completely SYMMETRIC; that is, the cause and effect are completely interchangable. I can just as well say that the absence of the electron on earth "caused" its presence far away as I can say the opposite (its presence far away caused its absence on earth). Thus, causality is not really violated, despite the transport of information over spacelike separations. If there was some required order of events (if, for example, the observation of one box resulted in the destruction of the other), then we would have problems.***
I agree that varying the interpretation of QM allows for a possible solution for Barrett's thought experiment. However, why is it that we must assume that the standard formulation of QM collapse is the guilty party? Why not also consider the formulation (i.e., postulates) of special relativity? Also, anytime we modify an interpretation in one area (e.g., collapse of a wave function), we are left with other holes in our interpretation that the new interpretation doesn't quite satisfy or it commits us to new worldviews that might be more drastic (e.g., extreme positivism or Many World interpretations, etc).
Warm regards, Harv