Let’s define, a cutting-edge as a wedge 0.08″ tall from the edge. And geometry: 0.01″ thick, 30* inclusive bevel, 0.5um apex radius.
When this edge subjected to damaging forces:
Pressure/Compression => increase hardness to limit damaging depth.
Lateral => increase strength and elasticity. In effective, broaden (broad & depth) affected edge area. Micro ripples and rolls take early loss of apex however blunted apex is thicker therefore reduce further damages. Low bending radius due to excess high hardness (matrix & carbide) lead to fracture to relief the damaging load. Fractured depth is usually 2x taller than ripple/roll. So even with soft edge, roll depth will be less than fracture depth. Yield early to minimized damaging depth.
Impact/Impulse (combination of compression & lateral) => increase toughness. We want to minimize radius of damage crater (roll/ripple/fracture). It’s a compromised among attributes because failure mode depends on impact load and steel toughness. A balanced attributes would be micro ripple and macro fracture. Roll edge would has less damage depth but threshold of damaging force will be much lower, so easy to roll lead to performance loss.
Steering => increase stiffness. Best way by increase steel volume (thicker edge & blade). Spring-tempered is probably most versatile but poor performance edge in compression & lateral cases.
BCMW chose micro-ripple & macro-fracture edge attribute because with proper steel volume per indented tasks, these kind of edge offers highest performance. Where performance defined as total work-done divide energy spent.