Positive edges designed to force sequences on steeper terrain, with their closed ends and hyper sloping backs. Turned the right way - the Stylets would make terrible, terrible tracking footholds. On a roof the slightly incut grips are roughly 3/4 of a pad deep and on vert they are mega positive.
Stylets are needle-like projections located on the mandibles and are used to penetrate plant and animal tissue. After piercing solid tissue, insects use the stylets to suck liquids from the host.