I don't think people are going to do that. DEF is cheap. You can buy it almost everywhere. The problem will be how well built is the High Pressure Fuel Pumps (hpfp). A lot of on road diesel vehicles, cars and pickup trucks have all had problems at first. The pump is lubricated by diesel fuel. If you have contaminated fuel (gas or water) it will fail and cause contamination throughout the fuel system. Ford, Chevy, Dodge, BMW, Mercedes, VW have all had some problems. They appear to be changing pump designs so this does not happen. Hopefully these on tractors are of new design.