"however, as much as I wanted to agree with you : NOW after asking ChatGPT, I have severe doubts! . . . . . . . . . . . . . . . .
No, simply being named on a Thai birth certificate does not automatically make you the legal father." Yes it does, but you don't have any rights unless the mother relinquishes custody or dies, but you are still the legal father.
Not quite correct. If he is mentioned on the birth certificate, then he is the legal father. You go to family court to be made the child's legal guardian. You are then responsible for the child and can stay in Thailand using Non-O extensions based on guardianship until the child reaches 20 years old.
Brandon Thurkettle: Most offices require that the funds come from abroad. If you use the Wise app, scroll to the bottom option for 'Reasons for transfer' and select 'Funds Most offices require that the funds come from abroad, so if you use the Wise app, then scroll to the bottom option for 'Reasons for transfer', which is 'funds for long-term living in Thailand'. This will then appear as an international transfer, but please note that it may take a couple of days or more to be reflected in your bank account.
157 days ( 2 x visa-exempt entries) per calendar year, unless you can convince the IO that you are a genuine tourist. If you want to spend longer in Thailand, then obtain a visa. An METV will give you nearly 9 months if you time your exit correctly.