Stop in for a cup of coffee

I like your idea, give that air no other place to go. I once removed my fan shroud from my Suburban, long story why, anyway it was running fine. Then went and towed an RV over a mountain pass to the eastern side of the state. Had to double back and put that shroud on cause the rig started overheating, dumb me!
Not sure where all your air is bypassing. Do you have a hood seal that comes down across top of radiator support?