the question is how much sugar stays dissolved in the steam. Not much. sugars are highly soluble so they would re-dissolve almost instantly. The sugars in the wort, that stay in the wort, will not caramelize. At any point in time that would be most of them.
Engineers go thru a lot of trouble to prevent dissolved solids from depositing in boilers (these are agents to prevent corrosion) because they hurt the vessel. DNB greatly reduces heat transfer so they try to stay below that point. We don't. When the water evaporates (forms steam) where do the solids go, some will go back to the wort, but some will temporarily deposit on the kettle surface. They have to.
Again, no one has proven that this occurs in beer.
FWIW. If you use this argument on the BJCP written exam, you will likely be raked over the proverbial coals