.Jwscud
Having spent around a half century in the industry, accumulating about 27,000 hours in PA18 thru to 777ER and instructed, examined and audited; I have never heard of Vc/Mc/Md, and Vd only in the context of a medical examination. What I have noticed though, with increasing frequency, is a focus on minutiae. For my money, if you don't know those values you are unlikely to be adversely affected.
Lighten up and concentrate on the relevant. Life will be far less stressful.
Maui