leveling from under (3 points)

I have a makerfarm 3d printer, and it is a little "soft" (I don't know if it is the right therm but in french I would say "mou") When I remove a 3d print, It happens that the leveling unajusts itself. I've heard that it is even worst with threaded rods printers. So I've been searching for solutions, I found 2, Here they are. They are independent, you can use only one or both.

1. 3 points leveling.
(with 4 points, when you move corner, the opposite moves as well, bad thing) To do that, I t