I agree, those methods are the usual processes but in the pursuit of more accuracy and better working methods degassing removes the micro non visible bubbles trapped within the liquid. The video above shows just how much air comes out of a small amount of carefully mixed resin. Without degassing you are basically pouring foam.
I haven't used west systems 105 epoxy and 209 hardener yet so I might be talking rubbish but I will try to video the degassing and levelling process when I get to that stage to see if it makes a difference or not.