Jeep has used different alignment specs in different years.
Remember the old saying, "In theory there is no difference between practice and theory. In practice, there is."? IN THEORY toe should always be zero. In practice, ball joints, tie rod ends, drag link ends, etc, all have small amounts of play in them. When the front wheels are not driving, they are being pushed by the rear wheels and their resistance takes up all the cumulative slop in the various rod ends. If the toe is set to zero, when all the slop is taken up the tires run splayed out. So the manufacturers specify a modest amount of toe-in (typically 1/16 to 1/8) to allow for this, on the theory that this will result in zero toe under dynamic conditions.
A shop I used to go to many years ago used a spring-loaded spreader bar between the leading edges of the front tires to take out the slop, then set toe-in to zero for all vehicles. It worked great.
Jeep specifies zero toe for the 242-equipped models because they assume (correctly or not) that a majority of drivers will leave it in full-time, so the front wheels will always be driving. That takes the play (slop) out in the other direction, so if the toe-in is set at 1/8 at rest, under full-time drive conditions it will actually be more and the outer shoulders of the tires will wear quickly.
