So, after finishing up all my skyshards I stumbled across this gem. The boss mob, Mati has a respawn time unrivaled by any other boss i;ve encountered so far. 10-20 seconds is the usual, sometimes instant and at rare times a minute. Every kill drops a minor soulgem, and a decent chance at green gear. Your bags will fill up FAST and OFTEN.
It would be pretty effortless to automate this farm. She always spawns at the same spot and she does not really wander off. All the adds in the room are seperate from her and do not join in on the fight.
Just remember to bring your backpacks and think of old fearfart when you're rolling in the cash.