This is the wording:
Anytime the refereeing body agrees a wrestler is blocking, interlocking fingers, thwarting his opponent and/or generally avoiding wrestling:
It doesn't say anything about the center of the mat. You can avoid wrestling in the center of the mat just as easily as you can on the edge. In fact you risk stepping out if you do so on the edge. This center of the mat stuff is USA wrestling's interpretation. With that said Nolf was all over the damn mat and not a peep. You could hear Slay yelling what are you doing?