This is what makes trying to advise people on this stuff so totally infuriating...and downright dangerous. Official rules notwithstanding, if you approach the right person at the right window at the right moment on the right day, pretty much anything could conceivably happen. Take that last sentence and substitute the word "wrong" for all the appearances of the word "right",and pretty much NOTHING could conceivably happen.
Did that, got "wrong"! Went to Macau office.
In 2004, I got 6 month F (business) visa there, no problem, didn't even need letter from Chinese company. This time, I had letter, duly decorated with company seal. "We don't do F visas, go back to Canada for that."
Previous trips, I've got 30 day tourist visa and others got 90. This time, all they'd give me was 15!
Previous trips, apply in morning, pick up in afternoon. This time, on Friday morning, "Come back Monday." A weekend in Macau sounds like fun (it was), but the woman I left in Zhuhai, expecting me back in time to take her to dinner, won't be pleased (she wasn't).
Going to HK in a few days with a friend who has done it before there; hope that works better.