Sorry I couldn't follow all your project results but it is well presented. I would like to see an English translation
The winding you show is normally called a wave winding but your pictures show well enough what you mean.
It does use more of the area with windings compared with the single layer approach but I suspect that your winding density is little better. You wind the bits that are not wound in the single layer winding but you also have longer wire lengths.
Axial machines are difficult to wind with overlapped coils, your method may be slightly easier than with lap coils but only with very thin coils. If you go thicker the overlap bits become awkward.
Your method probably works best for thin stators and thick magnets where the flux density in the gap is higher.
With certain shapes of magnet the overlapped coil may work out better but my attempts have been little better and don't justify the extra trouble.
With radial designs the overlapped coil arrangement is considerably better but the case is not clear cut for axials. You obviously find it better for your example but if you tried with the same magnets and air gaps as the common machines I am not sure it would be the case.
It is good to see someone trying different ways, I started that way but found that the same results could be got easier for the same cost with single layer windings if you use larger gaps and lower flux density.
Flux
