I can t recall ever observing another fly fisher using miniature egg patterns during a mayfly or a stonefly egg laying event. Maybe my recollection was clouded. Surely others would have tried this, if it worked we would have seen it in the literature. Even in streams that seem to support few other stonefly species I usually could observe the shucks of tiny winter blacks on the stream-side rocks. The stone fly nymphs will be recognized by the double set of wing pads.
Mayflies only have one set.
I tie all my early stones with one set of wing pads and the trout never seem to notice. I never could count the tails, so instead of two fibers I just tie in a small bunch. Remember even if a stonefly hatch is not happening trout will tend to feed on the predominate prey that is present. A stonefly is usually there. They just never learned to vacation in Florida.