I think it is used in lots of places where modern probabilistic inference would be a better fit. In other words, look at methods that are in Murphy's volume 2,

I think it is used in lots of places where modern probabilistic inference would be a better fit. In other words, look at methods that are in Murphy's volume 2, rather than 1, especially parts II, V, and VI: https://probml.github.io/pml-book https://probml.github.io/pml-book