I used rapidvisa.com. I remember one document had to be signed by my fiancé in her native language, thia. Anything that you overlook will cause a delay. In my opinion rapidvisa was money well spent.
I left Thailand for 3 months and Alex Baron did also. Maybe he can see the relevance to my post. I agree that nobody can guarantee him the same outcome, but many people continue to come here asking for it.
I stayed “ lived” in Bangkok 7 months 2017, Chiang Rai 7 months 2018, Chiang Rai 7 months 2019 Jan-August. All tourist visas from USA, extensions, and land border runs. I flew back into Thailand Nov 6th visa exempt with zero questions from immigration. I was in USA about 10 weeks and a 2 week vacation in Tokyo.
I did the exact same thing last year April - November, but I went to the border at Mae Sai. 60 day tourist visa, 3 extensions, and 2 land border crossings equaled 7 months. I was hassled by immigration this morning when I returned on another 60 day tourist visa that was issued in my home country USA. I spoke with 3 officers before they let me in. I was in USA 14 November - 20 January. Maybe I came back to soon.