My own understanding after reading Matzke is that the quantum-"half" of the universe is not multiple

I read somewhere that there is no need for millions of multiple simultaneous outcome for each uncertainty that resolved. Sure there are infinite uncertainties in what I'm going to call the "quantum basement" of the "classical universe" but the resolutions of the uncertainties occur once and one way. The fact that there are lots of them, essentially, doesn't mean that there are multiple parallel streams or branches however. I only means that from a certain point "forward" that there is a set of resolutions that occur to make the universe occur the way it did.