Your take on the salt breeze is interesting. But it's not just about affecting cooling. Salt air can make pieces stronger. It forces a slower, more even cool down. Controlled spaces lack that natural tempering. So sea air is worth it for better pieces.
Strengthen from salt breeze" seems like a stretch. Pretty sure the base metal quality matters way more than some damp air. @the_grant's natural tempering sounds nice, but a good heat treat in the shop probably does the same thing without the rust.