I agree that the crankshaft position sensor is absolutely the primary suspect. I've seen many with the exact same symptom as you describe.
Testing can be done, but with the way it fails for you, will probably not be of any value. You do NOT have to have any gauge issues to have a faulty crank sensor. Some do, but maybe only a third of them or so.
If you do buy a crank sensor, do yourself a big favor and buy a Mopar unit from Jeep. Aftermarket crank sensors are very "hit and miss" with a whole heck of a lot of miss. I will not install nor will I recommend anything but a Mopar crank sensor. Why take the chance for the most important sensor on your engine?
Search and you will find many threads of people that have suffered with aftermarket crank sensors. Don't be that guy.
99 Cherokee, 4.0 AW4, NP242
Past Jeeps: 49 Willys, 81 Scrambler, 88 Comanche
Without "data", all you have is an opinion!