Sorry, not really sure what you're referring to, but I can assure you there's no color fringing whatsoever in the original scan, and I can't really see it here- (edit- downloading the sample posted here and talking a look at 500%, I do see some slight aliasing on the type- again, not visible in the actual scan. I'm not at all clear on why that's happening.) and applying USM to any digital capture- single shot MFDB, multi-shot or tri-linear scan- is an absolute necessity. This scan, when USM is applied, can resolve down to the texture of the imperfections of the ink on the Colorchecker. (AND the dust!
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Refer back to what USM does- it defines borders, or boundaries between values of neighboring pixels. If there is no boundary, there's nothing that it can do to sharpen. That is, if the image has no ability to resolve an edge, USM will not sharpen that image. That is, to refer back to what you're saying, if the shot isn't sharp, USM isn't going to help it.
Every single digital capture device I've ever used, from the Leaf DCBII, the Betterlight, on through to DSLRs and the current major lines of MFDB, multi-shot and single shot- needs USM. I simply didn't apply it here to eliminate it as a variable for you.