In regards to your first paragraph, I agree wholeheartedly. Flies have triggering mechanisms that make fish bite in spite of the hook showing.
I ask the question regarding albacore/bonito because quite frankly I have far less experience with them than I do skinny water stripers, trout, etc. where a shiny hook can make a difference (and has in my past experiences). And since hardtails have such keen vision, even though they knife through bait at incredible speeds, I was wondering what the potential impact might be. You're probably right, a bit of flash off a hook near other bait probably doesn't look out of place at all.
Thanks for your feedback.