OK, I thought the entire purpose of Waygu beef was that it was really well and evenly marbled.
The secret to cooking Waygu beef is hot, fast, and short, because if the longer, slower cooking methods are used, the fat will melt out of the meat and you essentially end up with very expensive shoe leather.
Long, slow, moderate heat cooking? I'm not sure how that would really benefit a cut of meat like Waygu.