Be careful here. Other than the meat marking rules and the rules for types of greenery, KCBS has no appearance standards (on purpose). Thus "trends" develop based on what has done well in prior competitions -- word really gets around. Uniformity of size, color and shape is the predominant trend currently.
Grill marks (I think that's what you're talking about) can be very attractive but they are hard to "standardize" across six pieces. Good judges will evaluate the overall look of your presentation as well as any attributes of the individual pieces. In the last few years I've noticed the "grilled" effect getting less common and the cookie cutter sameness effect becoming more common. Neither is right or wrong. When I cook, though, I always worry about the judges who have trouble scoring something "different".
I judge mainly in the southeast and trends might differ by region.