What are the current rules for visa extensions in Thailand for tourists and how do they apply?

The user shared their experience applying for a 30-day visa extension at Samui Immigration, mentioning their TR visa and the early timing of the extension application. They clarified that this is their first extension and that they are ineligible for a 60-day Covid extension. Comments indicate that tourist visa holders entering recently need to first apply for a regular extension before being eligible for any Covid-related extensions.