Progress, perhaps?

Exported the preceding. Went to Forklift to see what was going to get sync'ed. If the September folder was there, then Hazel was still failing.

The September folder was not there. I could sync without telling Forklift to ignore the folder and its contents, which is the desired behavior.

Checked Hazel's log, and no reports of avoiding deadlocked resources, so it seems Forklift having the exports folder open may have been causing the deadlock.

If this post goes smoothly, I'll assume that was the problem and all is right with the world. Or at least the marmot.