I had the same confusion with three of my cars: a '94 Ford Taurus, an '80 Olds Cutlass, and an '08 Mercedes E350. I did a lot of research on the matter. To make a long story short, the difference between those gap measurements is slight, with little real world effect. A different brand of spark plug, for example, may have slightly different characteristics (the ground wire, raw materials, etc.) and thus a slightly different gap. Car manufacturers design an engine and designate a gap specification that is approximate, knowing full well the gap will grow as the spark plugs age and engine wear varies. The gap at installation thus depends, in part, on the length of time before the next scheduled plug replacement.
Feel free to experiment with different gaps without fear of damaging the engine. Car enthusiasts often tailor a gap to fit their driving characteristics. In general, a smaller gap provides better ignitability in cold weather, at idle, and at cruising speeds; a larger gap suits heavy acceleration, wide-open throttle, high octane gasoline or more advanced base ignition timing. A universal baseline gap for a low compression, gasoline engine has always been .044, exactly what Jeep recommends in your particular case. Assuming no special modifications, .035 is perfectly acceptable; .055 equally so. You could even try .075 in mild weather and assuming your engine is very well maintained. The spark plugs would be considered worn-out once they exceed about .090.
On two of my cars, I tried different brands of sparks plugs with different pre-set gaps by the manufacturer for my particular engine. With each set of plugs, I did indeed notice slightly different performance according to what I just described. In the end, the most expensive plug by NKG was the best overall in terms of idle, acceleration, gas mileage, and plug life mileage. It had the smallest gap, very fine wire and was made out of ruthenium.