Scanning black&white negatives: sharpness gains in using individual channels

Some people claim it is better to scan a black&white negative in colour mode and only use one of the 3 color channels. The reasoning behind this is that overlaying the 3 different scans of red, green and blue will be less sharp than only using the pixels of 1 channel.
Scanning in colour gives you the option to separate the 3 channels in photoshop and work with only 1 channel to create your image. I tested this theory with the image below. The image is shot on Kodak Tmax 100 and stand developed in Rodinal 1:100. Sharpness is not that fantastic due to the limited sharpness of my Epson v500. Even the very basic lens of the Franka Solida I that took this picture is outresolving the scanner.

In the detail below (100% crop of a 25Mpx scan) I compared 4 images: a black&white scan (using the 3 colour channels) and an image using only red, green and blue channels. I noticed a slight shadow clipping in the blue channel and an even smaller highlight clipping in the green channel. The red channel wasn't even filling the histogram, showing the most headroom.

Resolution-wise, I don't see a difference in the 4 images. Maybe the black&white scan (RGB image) has a slightly better tonality, but that's it.

Conclusion: it doesn't make sense to scan a black&white negative in colour mode and separate the different channels. Just scan your black&white negatives in monochrome mode.