door adjustment

I was pondering this bend the door strategy. Besides the obvious pitfalls you mention, it also would seem to be susceptible to the door resagging over time, i.e. the bends made simply unbend due to the door's weight and change in how the door hinge is held. Seems like this would work better when lowering a door, i.e. the metal is stretched rather than compressed, better tension to hold it in place. Not sure I'll try this technique, but I appreciate your creativity.