After a week of no activity, I removed the bait hive and the cone. Yesterday evening, I went to seal it all up. There were several dozen bees returning to the entrance. Some had full pollen baskets!
I have a trapout set up on the other side of the chimney, where I think the queen went when she left the first location. I sprayed beequick into the entrance to see if any bees came out of the second location (in case they were connected). None came out of either entrance. This is getting REALLY frustrating, both for me and the homeowner. Now I am thinking a small "after-swarm" moved in. I guess it's back to square one!