I assume it is in the documentation, but I am not aware of how stats are handled for uncommitted work. Obviously in the example you provided the table would be empty, but in your real tests do they start out empty? Would it suffice to use temp tables created like the regular ones and analyze after insert to ensure stats are up to date? Or would it make sense to turn off auto-vacuum/analyze during these tests? The workload is not expected to be similar to real world I would think, and so you don't need the vacuum and the stats update perhaps.
