Paolo, congratulations from me too. The video completely dispelled my critical stance on your project. The Air Tractor flies great! (I am Rolf’s colleague and the designer of the structure of Mozart I and Mozart II) 
Thank you Walter. To be honest I’ve been surprised too seeing the plane flying well at first attempt.
It has been a quite challenging design and preparation process as I had to redesign few times the tilting components to improve the CoG displacement and because of change in motors power… but finally it paid back 
Any update on the status of this layout? I am planning a UAS build with 3 tilt trimotor with 2 front and 1 rear.