I closed the lift gate on a leather dog leash and the friggin' leash was right on top of the latch. It would not open or close, but the "lift gate ajar" message is showing and all the interior lights were on. Yay.
Nothing in the paper owner's "manual" didn't have anything about manual override. The online version (which is the official REAL manual) has three vague sentences on how to manually open the lift gate. Massive amounts of Googling revealed no answers OR photos.
Along with my mechanical engineer son, we figured out to put the "3mm screwdriver" and what needed to move in the tiny slot. A bit of jiggling around and the door opened!
Insert a 1/8" flat head screwdriver into the small hole on the left side of the latch, move it slowly to the right, and the latch will release.
I'm posting this on a few Jeep forums just so the next person with a dog leash, backpack strip, or work glove stuck in their KL Cherokee's power lift gate, you'll see THERE IS A WAY TO FIX IT. Insert a 1/4" screwdriver into the tiny hole to the left of the latch, do not turn it, but move it to the right and the liftgate will open.