Research the WW2 German engineering, because they were out of refined fuel, the multifuel was a way to use battle field collected resources to keep the war effort going, the next war (WW3) was to be in Europe where refined fuel was going to be in short supply so the war planners looked to multifuel as the answer just as in the previous war, so the USA, England, and Russia (1000hp v12 multifuel), all had there multifuels based on the German design (in reality, these engines were almost clones of the WW2 design)
There really is not a "multifuel engine", what these engines are are DIESEL engines that ARE desiged to use DIESEL as its primary fuel that "can" run on battle field collected fuel to get the mission done, the engine is a throw away engine, if getting the mission done and troops out of harms way means cooking a engine, so be it, some fuels are VERY dry (gas for one) which will eat the ip, valves like a hungry rat., the other fuels, oils, ect WILL coke up the valves, ect. No one when designing or implementing the multifuel engine gave a second thought that these engines would be running today in our trucks, the designers would be AMASSED,