Digital ICE (and other related IR-based automatic dust/scratch removal) has problems with Kodachrome, due to the high density of the emulsion (especially for dark regions of the image). The image prevents the IR light from making its way through the slide, resulting in some dark regions being mis-identified as a defect.
If your software doesn’t have explicit support for IR-based scratch removal on Kodachrome, you probably won’t be happy with the results.
And FWIW, you can not use IR-based scratch removal with B&W film at all. Its silver halide chemistry is incompatible with the tech.
Check out what version you have. The least expensive version of SilverFast (“SE”) does not support Kodachrome. You need to go up to the next tier (“SE+”) to get Kodachrome support. See also SilverFast 9 comparison chart.
You can download a free evaluation copy. If you decide you want to keep it, you can buy a license key from their web site, which will permanently unlock all features available on the tier you paid for. Depending on how old your bundled copy is, you may also qualify for upgrade pricing.
According to SilverFast, using infrared scratch removal (their “iSRD” option) requires special handling when used with Kodachrome. if you have an installation with Kodachrome support, the software will automatically switch in the Kodachrome-iSRD software when you configure it for both iSRD and Kodachrome scanning.