Can I switch from a Non-O (single entry marriage visa) to a 30-day extension at local immigration without leaving Thailand?

The user inquires about the possibility of converting a Non-O marriage visa into a 30-day extension directly at immigration without departing Thailand. A commenter clarifies that while a 30-day extension is not available for a Non-Immigrant visa, it is possible to apply for a 60-day "visit family" extension, followed by a 7-day extension if it is initially refused.