As conterintuitive as it sounds, fishing an elk hair caddis on a downtream and acrross drift with intentional drag (i.e. just like waking a dry for salmon or steelhead) during an egg-laying flight does not spook fish. This is because the naturals are moving cross-stream as the lay their eggs. Most fishermen never become aware of this because the caddis flies are small (#14-#24) and don't make much commotion.
Unfortunately, when fishermen sees trout rising, they almost automatically assume they must use a drag-free drift like you would with mayfly duns or spinners because that is what most of the fly fishing literature says to do. However, caddis flies do not behave like mayflies, so using the skated presentation is appropriate since it imitates the behavior of the egg-laying natural.
During the 12 years I lived in Montana, the skated elk hair caddis was guaranteed to catch fish during a caddis egg-laying flight in the late afternoon/evening. Surprisingly, I saw very few fisherman doing so despite its obvious effectiveness with those who did.