Well based on that, I'd have to concede it's looking like steel is the final product. Now google how many Miata's have been suspect of biting the dust from rust ingestion from a BEGi turbo kit.. or any other vender - make model.. Since those kits have been around since ooh what 1994 surely if it's an issue it would have been noted by now.

Do I like the idea, no... no more than not reinforcing the sway bar brackets from the factory..
Am I going to sell the car before mine have a chance to break.. nope.. not a deal breaker on ownership..