Well, that was markedly less frustrating. Got the next few boxes on the map worked out, though I haven't figured out an elegant (and efficient) way to make the hierarchy update. I'm actually considering using a single query for each node in the hierarchy so that the group-watcher will reload its own children every X minutes (rather than having a single repeating function doing it for the whole scanner every X minutes). Getting out of the monolithic scanning mindset is harder than you might expect.