I think at least having a way to redirect suction and blowing from the tool would be a good idea. Maybe another solenoid between the pump that can switch whether the pump is sucking or blowing, a much larger needle that can fit the whole seed, a mesh to keep the seed and dirt from going into the tube, and once it sticks the tube into the ground, reverse the suction and blow the seed and any dirt out.
With regards to losing suction, I’m going to experiment with putting a thin layer of silicon over the top of the puck in the area where the suction tube is. Hopefully the rubber gasket on the UTM and the silicon on the seeder tool together will help.