Last time out, I was stopped at a pretty good decline.. I was sitting idle for about 5-10min and then it started to idle rough... where it seemed to go lean? I shut it off. After about 5 mins or so, I fired it back up to go down the hill and its seems ok.. no issues after that..

Any idea what that was?

 

May have been fuel pressure drop. Have you read fuel pressure with the jeep on different inclines? This may lead you in the right direction, try to resim the position of vehicle with taking a reading.