The point is more that there is no need for a breakthrough, because there is no need to postulate a mechanism for actual collapse, since decoherence is sufficie

The point is more that there is no need for a breakthrough, because there is no need to postulate a mechanism for actual collapse, since decoherence is sufficient to explain the results of experiments. I'm not sure what your argument is, but nobody is proving a multiverse, it's just an observation.