I've thought about it, but to maintain that for more than a strike or two I'd either need more spirits contracted or more complex ones. [ At least, in his own experience, from his own tests of it. ]

It's more efficient usually to have them work around on my lungs or ankles or parts of my body to increase the speed there. Wind's more sympathetic to flesh than it is to most metals.

[ At least within the Logic he knows. ]