Not to mislead, but the issue I mentioned happened in 4WD PART TIME. Not 4-Low. Just to clarify.
I like your info about the reverse gearing in the 42RLE trans. That makes sense. I've had it shudder a few times as you mention, but it doesn't stall during those times.

lol.
I wonder if it is as simple as the gearing issue you mention, in conjunction with buggy (first year) drive-by-wire electronic throttle calibration. I bet that's all it is. Maybe the shudder is common on all the 42RLE Liberties, but the new computer/throttle control simply doesn't have any signal to slightly bump the throttle up.
Hmm...