Does the artless flute attack count as melee? That would at least make it not completely useless....color me unimpressed. The capstone turns a melee attack into an AoE striking Very Close Range, and that is it. If we were good at melee attacks, liked to be at close range, and had problems dealing with crowds, this would be a nice addition to our repertoire. As it stands, none of those apply.
Kind of a bummer for Ling Qi that the sect's trademark arts revolve around melee fights. Even Argent Mirror... useful as it has been, I believe we have Word of Tutor that it's a perception art meant for melee fighters rather than ranged attackers.