Just out of morbid curiosity, I've got 2 initial UOA's here, both on Jeep 3.6 variations. The first Jeep had its initial oil change at 2,007 miles. The 2nd at 4,658.
So here are the Jeeps:
Jeep 1 2018 Jeep Wrangler Unlimited Rubicon, 3.6 Pentastar, ESS using the starter motor, 6 speed manual...