Yes, I know all about "The Mismeasure of Man". I've seen it used to claim that IQ tests are inherently racist. It's basically playing "guilt by association". I've already given you the non-racist use. If we are going to set public policy based on the assumption that there are no significant differences between the races (or even the sexes -- yeah I've heard people claim that), it would be nice if science could determine if this is a reasonable assumption to have or not.
If black kids are scoring one standard deviation lower than white kids on IQ tests, it would be useful to know if the cause is something we can do something about (culture, instruction, etc.) or something we can't do something about (genetics) because if we make the wrong assumption, the policies inacted will, at best, be useless and, at worst, be racist. You can't do that if the entire subject area is considered off limits.
For the record, I don't believe that average IQ differences between blacks and whites as populations are genetic. I do think they are cultural and/or environmental. Perhaps that's why I don't fear such research, so long as it's done properly. I can see great value in demonstrating that IQ and achievement differences between the races is cultural rather than simply assuming it and declaring the subject off limits. That only makes the real racists think that science has something to hide. Basically, I think that such research could provide a fatal blow to some racist ideas that have been carried forward from those early days of measuring skulls.
But there has been much good Science done on the subject and the verdict is in. There is much less actual difference on a molecular level between all human populations than anyone ever assumed. Anyone who says that the work hasn't been done, or that the definitive answer is to be found in the shape of skulls rather than in genotype, is trying to sell something and it usually isn't something nice they are trying to sell.
And the difference is cultural, not genetic. Middle class black children raised in houses with books do much better than lower class white children raised in houses without books in just about every measure. Family income and literacy are far better indicators of academic success than skin color.