The novel elements of this have already been released individually, particularly the lattice-free MMI training which can be run through Kaldi's nnet3 configurat

The novel elements of this have already been released individually, particularly the lattice-free MMI training which can be run through Kaldi's nnet3 configuration. Also, don't assume that a 0.4 % increase means drastically better real-world results. This dataset has been around longer than I have, so by this point Microsoft has just gotten really good at tuning.