After a few days of appreciating that the Red (area left of the vermilion) is more protected by mucosal surface than the skin side, do note the position of the muscle (M). While I cannot accept more damage will result by playing only in the red, I do still have concerns as to the optimal use of the muscle bands (M) as it relates to the red and then across to the other side of the vermilion. With the trumpet mouthpiece only on the red, that muscle band is positioned totally off the rim of the mouthpiece. With the traditional mouthpiece placement that crosses the vermilion (V), the muscle is included within the mouthpiece. THIS is the big difference. With the muscle in the cup, much more can be done to move and fine tune the lip as it plays through notes. I would suspect this would give more control in slotting, provide more fine control of bending, embellishing notes, and improve endurance as the muscle is prone to less movement, less fatiguing when splinted within the mouthpiece. This is why I would think there is more advantage not just playing in the red, but advantage to those that play crossing the vermilion boarder. Moral of the story: Not a fan of playing entirely in the red, not because of the myth that this area is more prone to damage, but rather from the perspective that the histological placement of muscle within the cup for lips crossing the vermilion provides easier enhancement of control to overall playing.