Immigration division 1 in Bangkok have produced details about how to do an extension.
And as with any extension, apart from maybe the standard 30 days on a tourist entry, people should go to their immigration office before requesting the extension to find out what that specific office requires.
This YouTube guy is just like all the others; we’re consuming opinion when we watch them.
A similar experience that I’m involved with. Application submitted to HCMC 29th January. Obviously due to the holiday the first day of processing was the 3rd February. Request for additional documents received Wednesday (5th February) document uploaded that afternoon and an hour and a half later, visa approved.
So total time excluding holidays/weekend was three working days.