Near immigration, but on the main road.
If you combine it with a trip to immigration, eg for 90-day report, motorcycle from immigration to MFA consular division 3 minutes, 20 B.
You need an online appointment. People who didn't have one were sent home.
The legalization service of MFA at MRT Khlong Toei has a better reputation, but at this time you get only appointments at CW.
Once at MFA, you get a queue number. Your appointment time doesn't matter any more.
You can book appointments at times like 12.30 or 11.30. Not recomended. They don't publish a fixed lunch break from 12 to 1, like immigration does. They just worked slower and slower (because staffers would disappear for lunch ) and stopped completely at 11.15. Counters were still open, so nobody dared to leave - you wouldn't know when they start working again (it was about 12.15, slowly gathering speed).
Waiting time was 2.5 hours. Its faster early morning.
Express service (means same day, you still have to wait those 2.5 hours): ask actively for it. They do it for some documents (different from what they write on the website) for a 100% surcharge. Took 1.5 hours. You have to bring your receipt to the Express counters 1-5 when the time is due (they tell you how long it will take), then you are called by name.
Price 200B per sticker (1 sticker per legalized signature). Express 400.
Quite a few people's documents were not in order. Call the call center before you go.