Does using wings with different wing loadings work the same as a swing wing, without swinging the wing?
For a triplane, wouldn't you want the top wing for flying and the other wings just for takeoff?


No.


Form drag is proportional to dynamic pressure and frontal area. By varying the lift coefficient between the planes you are not doing much to the frontal area, so the form drag is roughly the same.
Induced drag is proportional to square of lift and inversely proportional to square of span and dynamic pressure. By generating three times more lift with one of the wings, you are making it produce more than tree times the induced drag.

It is not all the nine times the basic equation suggests, because the efficiency is still significantly reduced by interference when all the wings are producing lift, but it is still worse, and it is worse whenever the lift is not distributed uniformly (maybe the interference makes a slight increase in the middle wing desired, I am not sure here, but it won't be big difference).


So the configuration is not better than evenly distributed lift in any flight regime.