Do I need an MFA stamp on my Affidavit for the NON-O extension, and when can I apply for it?

The individual, a Belgian passport holder, is seeking guidance on two questions regarding the extension of a NON-O visa for retirement in Hua Hin. First, they inquire whether the affidavit they have obtained needs to be stamped by the Ministry of Foreign Affairs (MFA). The response indicates that typically, an income certificate from the embassy does not require MFA certification. Second, they ask about the appropriate timing to apply for the visa extension, with the answer suggesting that it can be done when there are 30 days or less remaining on the current permission to stay.