This ALL wrong. All of it. Direct injection is NOT the definition of diesel. Compression initiated combustion IS the definition of the diesel cycle irrespective of fuel.
Direct injection has been used on gas engines as well as diesel. Mercedes Gullwings from 1955 used mechanical gasoline direct injection as did some WW2 German aircraft.
Electronic direct injection for diesels was developed over 20 years ago. Using it for gas engines allows compression ratios as high as 13 to 1 with pump fuel because of the cooling effect of fuel evaporation when injected. Much greater efficiency than a 6 or 7 to 1 air cooled stationary engine