Have not heard of adding ATF to diesel fuel , but I have heard of adding one ounce of TC-W3 2 cycle oil to every gallon of diesel fuel. There is a lot of information on the web about the 2 cycle oil. I think it's moparman1973 that does a lot of the information. I ran 2 cycle oil as an additive in my old 2000 dodge diesel for 50,000 miles with absolutely no issues. Just an extra insurance if you will with the VP44 injection pump.
Matt