Hey DSD. Well, I don't know if this helps, but, I know I often hear and also experience that with salmon in rivers, they seem to be more aggressive as soon as the sun is low or behind clouds, or a hill. But I think that's only because salmon, as with winter steelies, tend to swim or move up during low-sun or dark hours, so you get more hook-ups because fresh fish move into the next run or pool. I think that's why these guys are getting great success at first light. But I can't help but think that's also because the pool has rested overnight, the fish aren't as spooked, with tons of hardware and bait swinging by, so they're virgins in a sense, each morning. I don't know, that's my observations thus far.
But that theory on the fish, facing the sun, and not biting??? I wouldn't doubt it. It makes sense. But I guess it also depends on the water clarity, etc. With darker water, they don't seem to be as spooked in general...even on a bright sunny day... and of course, when the fish are out in the chuck, they seem to be all-together different than when they're in the rivers. Hey, I always say, "whatever works, do it."