I'm scanning using Vuescan with the Epson V700. I scan at 6400 dpi and then have the scanning software downsample. I scanned a small test swap of a 4x5 file, comparing 3x- and 16x-multi-pass. It seems to make no difference. Nor does either offer an advantage over 1 pass (not shown). [all of these include multi-exposure too].

So it seems to me like multi-pass isn't doing anything. It is supposed to reduce noise. Thoughts?