AlanB,
I have toyed with the idea of singing the end of the shuck. But, when I think about the two guys who came up with the idea of using shucks on the regular comparadun, they did so because the individual fibers caught the light and produced a "sparkle" limiter to the shine on the shucks of insects.
I am sort of torn between the "closed end" shuck and the shuck as tied by Craig Mathews and Jon Juracek. So, I end up in their camp as I have been very successful with sparkle dun style patterns.
with a slightly singed shuck end.