Ah, something becomes clear.
Chuck Nickerson
In sharpening profiled irons, your first step is docking the cutting edge at 90*, and I do this.
I recall two reasons being given: it protects the edge from heat during grinding, and it gives the
30* honing work a plave to happen.
There's also a third reason: by actively removing the leading part of the blade, it eliminates the
wear bevel on the face of the blade.
I guess my normal plane and chisel blades just became even more a comsumable item.