Here's the roller tip side view. If alignment isn't really close to perfect with a higher lift cam there will be contact between the arm and the valve.
Another thing I'm not crazy about with these rockers can be seen in the picture, especially the rocker on the top right. Whatever process is used to peen the ends of the roller tip shaft also bends the support arms. When the arm bends it twists the roller tip. This leads to point contact on the valve tip rather than line contact. I've checked a few on a measuring stand. The roller on some of them is twisted 0.0015"-0.002".