Interesting observations... I would love to have a peek at your journal
I think you're dead on with light conditions. At Sekiu while most of us were kicking back for a while in the evening the local boys would go down to the gaps in the kelp near the Caves and cast buzz bombs into a high tide. They would consistently hook and sometimes even land summer kings up to 25 pounds.
It's a known fact that kings come into the kelp at dawn and dusk in the straits in July. I often wondered if finding an inshore hunting route at dawn or dusk with a grainy sinking head line and a good looking herring fly or squid fly or candlefish pattern wouldn't put a tyee on the line with some patience and luck.
AJ McClane documents radio tagging study results that document a distinct movement of chinook to the shoreline at dusk with withdrawl to very deep water in morning. I would guess that one of the most influential factors would be targeting "o'dark thirty".
I wonder what would happen if someone who works in Seattle hit twilight in the tide changes at Alki from mid-July thru August every dawn before work... hmmm... wish it were me!