Thank you for your reply, Mark. Yes, it was a feature found in version 6 of the software. I guess they did not migrate it to the new version.
Actually, the Auto USM feature worked surprisingly well. I've been trying for a few days now to match the results between a scan done with version 6 using the Auto USM and version 8 with its various USM options. The version 8 scan doesn't come close. Maybe I need to incorporate a different workflow and hand off sharpening to Photoshop or Lightroom?
It probably wouldn't hurt to buy your book, either

That's an interesting insight about the difference of sharpening quality you are finding between version 6.x and version 8. The manual controls in version 8, especially with the expert dialog give you more control over the effect than was available in version 6.6, so *in principle* it should be possible to do even better - but with these things, from a user perspective of course only the results speak for themselves. I can't know, but perhaps some more experimenting would help?
I do have quite a bit of material in the book on sharpening scans for all four options at play here: SilverFast 8, SilverFast HDR, Lightroom and Photoshop. One can obtain good results from any of them when used properly (which does have a learning curve); but that said, sharpening film scans - and all the more so if they are from colour negative film - is kind of a fine art, so when I really want to exact the most control over process and precision of outcome, I'll not sharpen in scan software at all, but use Photokit Sharpener 2 in Photoshop.
BTW - if you are thinking of buying the book - you don't need to take on much up-front risk over this - on the SilverFast website there are three extracts of content posted for free download, which should give you a pretty good idea of what you'd be getting.