Fortunately, I've yet to have any issues or leaks from the fuel system. My pump has Nitrile seals to start with to deal with the low sulpher fuel. When I've run JP-8, I'd never have more than a 50/50 mix with diesel.
If you google online, there is a book published by the US Army that did a long term study on just that very subject because the military commonly shares jet fuels with the diesel powered ground equipment to save weight and simplicity with everything running on a single fuel if diesel gets scarce. That's another reason why nearly every military vehicle is diesel or turbine powered. In short, according to the report, you can run diesel engines on JP-8 (tuned to run properly), but at risk of accelerated wear on engine and fuel components if long term use is expected.
I'm thankful to have the old 12V engine, which is SO tolerant of various fuels. My engine has successfully run on diesel. . (duh), kerosene, JP-8, engine/trans/gear oils (non-synthetic only!), biodiesel, and cooking oils.