I thought of it, but I guess it's too much for the size of the stage (note that for this to work I've deleted the courtyard)
Also, a very big and complex platform I guess, it would be strange when landing.
By the way, new picture with the fog:

Looks fantastic while playing. Maybe I post some video later.
fog looks great (I saw the video). For flying version, maybe it would fit the filesize if you remove most of the Super Smash Bros stage - leave only the top and bottom platform. This removes the tower, the blocks at top left and top right, the trees and sign, the bumper, and the foundation of the stage (grey block under it, including the sideways platforms). This would also be less complicated for landing - only two parts would need to hit the ground