So I was watching Sabine Hossenfelder's youtube video. I am uncertain if she does it justice. My understanding of the many worlds is as follows: The universe evolves according to the Schrodinger equation at all times. The non-unitary evolution of the wavefunction at a measurement is more a consequence of not taking qubits of the density matrix of the measuring device into account. Similar to the NOT gate being non-unitary but the CNOT gate being unitary due to ancilla qubits.
The question about why do we perceive that a universe in R rather a Hilbert space is because there is a non-trivial one to many mapping between the Hilbert space and many real worlds. Is this an accurate picture of the many worlds? Is there a rebuttal one can make against this? Where can I read about ponderings of the many worlds in this light?