That's flat out embarrassing, Aineo! I have access to a little data in this area is all! I'm perfectly willing to be corrected if there is data which disagrees.
The vapor canopy probably did exist, as droplets still in the thermosphere may be attesting to. It probably did contribute heavily to a uniform environment/ecosystem before the Flood. It also probably was greatly reduced or destroyed by the Flood, but may have, in part, contributed to the time of moist conditions being maintained after the Flood and before Babel. I should have given a little more credit where credit is due to the probable existence of the early vapor canopy.