Everything went smooth and really quick. They do not ask for a printed online appointment email anymore. When you are in the queue, the officer is asking who is booked online and letting you go straight to the counter. I walked in 8:24 and walked out with my passport and extended stay stamp at 8:49. I could finish even a few minutes earlier if I had TM7 filled out in advance.
Thank you very much for advising me about online booking! ☀️