This is more performant(can be ignored but an extra) due to nature of lookup tables. Also it is more compact and has ease of extension. It is a little bit scary at the first sight though.
This is much better for understanding whats going on. Also as the reference links are pointing to 26/04/2018 version, it helps understanding if things have been changed etc.
This steps was only helpful while implementing the algorithm. And could be useful while comparing with the W3C specification, but they take up too much space.