I did the original layout in Balefort with the three Arts. I put em on the treasure chests so people could see them when there was a mob around them. I'll have to check the trigger volumes, but they may be the same as the ones in AL. The difference may be that there is only one in Travellers' Outpost, and the three in Kraag are so spread out that lots of people just hit the first one they see.

Still, super interesting to me...