From your response you might have misunderstood what I was saying. The diesel will not start doing ESS until it has run a little while. If you don't have about 20min or maybe even 30min of run time on a drive it is possible you've never got the diesel engine to a point where the software will start turning the engine off.Yeah, i have over 1000 miles on the car now and I've never had the start/stop engage. Guess I'm lucky? I could try to turn it on and see if it actually works, but if everything works otherwise I'm tempted to not poke the bear.
I've also read about how some people can brake in a way that tricks the vehicle into not killing the engine. Maybe you naturally brake in a way that engages this bypass. This is something that people do across brands, often there is a way to brake and stop and then do a slight lurch forward before the engine is killed which stops the ESS from being actived for that stop. But with this I don't know if and how it works for the jeeps.
I'm not saying you didn't get lucky and the ESS doesn't work properly, it just seems more likely that there is another factor at play creating your lucky situation.