Just tried that in my JL and it kept telling me to press the clutch. I tried it in 2H and 4L.Yeah, I used that on an old VW Bug that I had in my younger days. It was useful to get the vehicle out of the way if it vapor locked also.
This looks like a capability that the stupid push-button start/stop has taken away from us. From what I've heard, it was a feature that was sometimes used by people to restart their vehicles while off-roading on steep terrain.