Diesel fuel contains more paraffin wax than Jet A/A1. This wax starts to solidify at temps below zero and can clog filters at -10c. As tank and pipe temperatures can easily drop below this temp, there is a distinct possibilty the fuel lines could become clogged with wax before the fuel heat exchanger warms it up. The answer of course is the use of additives to lower this temp, so you may as well just use jet fuel in the first place.