What are the requirements and experience when applying for a visa extension in Thailand?

A user details their experience at the immigration office in Bangkok (MTT), Thailand, where they went to extend their visa. They received an 'under consideration' stamp valid until November 30, after arriving at 10:30 AM and leaving by 11:30 AM. The user emphasizes that an online booking was required for entry, and many who arrived without one were turned away. They also noted that no additional documents or cash were needed for the process.