But tunneling, and atoms even, are classical concepts, not QM concepts. I'm confused here, but I suspect that others are as well. My impression is that the best pseudo-classical perspective is that anything can appear anywhere at any time with low probability (!!) but that it's confusion to think in terms of classical objects doing anything but following classical physics as the classical particles, indeed the classical objects, simply ARE the math of classical physics which is approximated by QM.
This is a nit to pick perhaps, but it seems to me that the proper understanding of Boltzman Brains involves this line of attack as well as a Turing Machine refoundation.