Ok so I went out to Yhot. Jungle as lvl 31 WHM/BLM
I pulled out the NPC and he stayed for a whooping 45 min!!!! Not 30 or 40 but 45!
We we're doing the usual chaining Mandys and pulling the occasional Goblin smithy.
We'll after the 42 min passed our thf left us so we sat for 3 more min trying to find a replacement when my NPC decided to leave. So there you have it 45 min is my record
I have absolutely no clue how much exp we gained but we did at least 14+ fights.