The Book says to blanch greens four minutes, but since I don't cool them down, I do more like a minute (or more for very thick leaves). Then the hot leaves go on the rack and immediately into the dehydrator and they finish 'cooking' on the rack. They stay a nice, dark green all year.
We had a cafe that made kale chips to go alongside their sandwiches. They massaged the oil into the leaves and that must break the fibers down...they looked cooked when they went in to dry. Blanching wouldn't be that important for chips, which aren't meant for long-term storage.