I have had extension of stays for 6 years. I recently left the country (with a re-entry permit) and when I returned on 14 Feb, my immigration office said I have to go to the office in person for the 24 hr notification and also for the 90 day report because the online system is currently not working. I understand there are 70+ offices and your mileage my vary but that's what i was told by the people that should know.
Does this add to the existing extension or is it deducted from the next? Or in other words, if this 60 day extension is obtained, does the next (one year) extension start new when the 60 days expires?
I use Nakhon Pathom, they seem less strict than many offices I read about. Go there and speak to the girl/young woman at the desk just inside the door. She's very helpful.