Posting from Immigration office, Krabi. Applied for residence certificate and got in 20 mins (perks of small city as it was first day after vacations).
They took passport. Asked me to fill a form with basic information (name, address, purpose). 500 Baht fee. And officers printed, signed, stamp right away. In 20 mins I'm outside.
Everything should be in order of your TDAC, TM30 filled, visa sorted as they verify online.