Recently I read the biography of Erwin Schrödinger by John Gribbin, who points out that E.S. proposed a many worlds interpretation of quantum theory several years before Everett. This got me thinking how to make sense of m.w.i. after all.
As I have pointed out several times on this blog [1, 2, 3], a major problem of the many worlds interpretation is the derivation of the Born rule.
But I think there is a way out: If qubits are the fundamental building blocks of our world, then every event could eventually be reduced to a series of yes-no alternatives of equal probability (an ur alternative) - and in this case the m.w.i. gives the correct probability.
I think this would also take care of the 'preferred basis' problem, because if the world is fundamentally discrete, the 'preferred basis' would assign two unit vectors in Hilbert space to each qubit.
C.F.v. Weizsäcker proposed his ur-theory many years before the term 'qubit' was invented and if one is serious about m.w.i. then it would be a strong reason to consider ur-theory or something similar (*).
Much later the idea that our world is a large quantum computer has been investigated e.g. by Seth Lloyd (but I don't know if it would work with urs).
In this case the task to derive the Born rule would be equivalent to derive QFT as we know it together with general relativity from ur-theory and/or from the behavior of large quantum computers.
(*) C.F.v. Weizsäcker himself was a believer in the Copenhagen interpretation and rejected m.w.i. explicitly in his book.