Does the Fourth Circuit's practice of not addressing erroneous Sentencing Guidelines calculations but affirming a sentence under 'assumed error harmlessness' review violate Gall's directive?

QUESTION PRESENTED FOR REVIEW 1. Does the Fourth Circuit’s practice of not addressing erroneous Sentencing Guidelines calculations but affirming a sentence under “assumed error harmlessness” review violate Ga//’s directive that a properly calculated Guidelines range remain “a meaningful benchmark throughout the process of appellate review”? i