Never tried walking both front lines, but I usually walk the upper front line when its nuking. Sometimes the kite does a flip before it lies down, this might stop that. Hmmm
This morning I self-landed my 12m kite at 3rd Avenue using this technique in lighter wind. The kite stood steadily on its wing tip as I walked both power lines. Works like a charm.
Not more violent self-landings ... this is way more civilized without the risk of damaging the leading edge.