im not an avid dry fly chaser, but I do feel like offering something to help YOU stay the course via perspective.
You're talking about chasing a fish that needs to be and act a certain way at a certain time at a certain place.
Here in the midwest, the irony is this: we have tons of fish, but often:
1. water temps that are ideal live a very short time due to our weather--affects metabolism.
2. the grabbiness of fish can often be less so due to genetics and non native species.
So, consider that we also have that unicorn factor here in the great lakes, but due to different causes.
Catching them on a dry has, even more things going against it.
Yet, still we look for that magic moment. even despite that.
Ive only had 2 encounters. Ive made probably a dozen attempts in earnest. mostly with our summer run strains, and then again with our fall run fish early in our season (october) when water temps still have them amped up. My one encounter came when I swung silver spinners without a hook, got a roll, then thew in a ginked up muddler on a thin hook and left the head really scraggly and waked it immediately afterward. I happened to know that a pod of very fresh fish had just arrived. the second time was on a larger (size 8) elk hair caddis with the lower body hackles clipped short.
good luck and mahalo!
What I lack in skill --- I make up for with enthusiasm.