Hello all, sorry for the late reply. Thanks for all your help. To put a bow on this thread, the answer was indeed CPS. I swapped it out for a new one and the issue dissapeared instantly. I also noticed that on my old CPS the wire appeared to have been slightly melted due to its proximity to the exhaust on cylinder 6. To anyone chasing this issue, make sure to route the cable in a way that it keeps it's distance from your exhaust. So far the crown auto CPS has been working fine. I'll update this thread if it ever gives me an issue.

It makes perfect sense now that the CPS could cause a no code misfire, since (to my understanding) the CPS is what detects misfires in the first place. Since CPS signal was cutting out momentarily, the engine had no idea that a misfire , or more accurately grouped misfires across all cylinders momentarily, was happining.

 

After reading this thread, I am reminded of a similar symptom on my 98 XJ 4.0. The engine was beginning to crank and crank upon starting and was taking longer and longer to fire. Over a month, it was almost impossible to start - I was thinking Fuel Pump issue. I would turn the key to on / then off several times in rapid succession to cause the fuel pump to feed some fuel into the rail. Upon trying to start, it would "bump" once and then just crank and crank - but no fire. It finally started, I took it out on a highway trip, and it quit suddenly - one moment it was running well at 70 mph, and suddenly it was as if I turned the ignition off. Coasting to a stop on the shoulder of I-95 I parked it for a minute then repeatedly tried starting - no fire at all! Long story short, I had it towed to a local shop nearby who was familiar with the 4.0 Jeep engines. No codes were showing, but he suspected ignition when the fuel rail had good pressure at the schrader valve!! Pump's gotta be good! Connecting a screwdriver to a spark plug wire and then tried starting, he saw NO SNAP! There was no spark getting to the plugs. Backing up the troubleshooting, he found the culprit to be the coil wire that runs to the center of the distributor. The end of it was badly corroded and worn. It looked like the end of a rope - all fuzzy and no metal tip! Installed new wires, plugs, rotor and cap and it runs like a raped ape!
Lesson learned: Always check the simple things first!!