It's the Unusual Camp way up in the West-Northwest, on an unused island.

Thank you! I found him and got the inquisitor spawned. However, when trying to do so for the Dust Reavers Bandit Boss, it doesn't seem to work (have gone away and back couple times, still no show).

Can always import and see if that helps. For me it worked fine through several uses, but I've heard others that couldn't get past the first use. Not sure what's wrong with it since it seems fine on my end. :/

I just go to the spawner, and tell him who I want to spawn. Swim to the peninsula with the lab on it, then return. Kill the guy, talk to the spawner to reset the location, swim to the peninsula and back, tell him to spawn someone else, and so on.