Keep it stupid simple
In CDG, one of the de-icing trucks in front of the A/C keeps its crane right in front of the cockpit windows (2 meters or so). I mean right in front of your nose ! It is impossible to start taxiing before de-icing supervisor declares the area clear of personnel/vehicles. Then only the crane is removed from view... This makes de-icing ops a little slower than e.g. in scandinavian countries but is definitely safer. FFT.