I run mostly ATF in my diesel fuel to boost cetane. I also use Marvel Mystery Oil as a fuel additive alternately.
I've been told that ATF can screw up injectors in diesel and gasoline engines. For 16 years I've been using a mixture of Power Service (to increase the cetane/clean injectors) and TWC3 2 cycle oil (to lubricate the injector pump and injectors). Every time I fill up I add 7/10 of an ounce of the mixture for every gallon of diesel. I used a MMO/Power Service mix for about a year until I found out that 2 cycle oil is a much better lubricant than MMO. MMO is almost all mineral oil with just a few other additives, it does smell good though..
Bad for common rail diesels, and really bad for DPF and SCR.
300,000+ miles on my 99 7.3L Powerstroke, all of them with light to moderate towing, & the motor still has all of its original internal parts. It runs better now than it did when I drove it off the lot. I have been driving tractor trailers as well as my own personal diesel truck since 1987, which is where I began using ATF in the tank. Have never experienced a single malfunction or concern, ever. Fuel mileage suffers without it given this water they call diesel these days. Noticeable upgrade with it.