Redoing the shot with blender because the original synfig project gave me many problems.
Really blender greatly simplified the work in 2D before the interface did not allow to quickly see the different planes and the simple images were located in XY mode instead of XZ. That among thousands of other advantages of the new blender 2.8
The layout of the scene works both in orthogonal and perspective, I am thinking that moving the camera generates the sensation of space in a “real” way instead of animating each layer separately.
You can automate the crane so that if I move a bone it rises or falls, the mechanism still has to turn when it moves. I also have to make the chair move along the long bar and add inertia to the character sitting on it so that it shakes next to the crane.
These days I continue