You've apparently never lived in and tried to maintain Chrome on a DD in Hawaii.
The floorboard brackets SO FAR on my FLTRSE3 are OK, as long as I keep themn clean and polished. At base they are a ferrous metal and give relatively few problems. The brake pedal on the other hand is aluminum, and aluminum is porus and if oxidation has begun prior to plating, you cant stop it.
The problem is so bad, HD will warranty ONE piece of chrome during the warranty period if your bike is garaged here. Anything else is considered "normal wear and tear" for this environment.
You know, there has to be a price for living in paradise. If you would prefer living in the armpit of the country, perhaps you and I could trade places.

Here's the thing about chrome plating, and you already hit on it in your post. If the base material is already oxidized or contaminated, the plating will not hold up. Of course, the plater is supposed to control those things and not just dump oxidized parts into the process. That's why I say the peeling issue is a manufacturing defect and should be warranted. Now pitting is a different thing and can be related to all that salt air over in paradise, or road salt here in the snow belt.
Btw, just because H-D says something doesn't mean it's gospel. They have been known to scrounge for every possible excuse to deny warranty coverage, and just love to tell folks that's normal, they all do it, we don't cover cosmetic items, it failed because of your modifications, we just don't like you and wish you would go away, etc.
Jerry