Most of the agents have a good relationship with the Immigration. Hundreds of Falangs are happy with their services. Personally I didn't go this way, because I had a working visa. But two of my neighbours in the condo where I was living, had never any problems with this "short cut" visa. Probably important to know how many years your agent is already in business. My opinion, really nothing to worry about. Good luck 👍
Google Pattaya immigration agents. Inquire and you will see how easy it is to get the Non-O and after the one year extension. You even don't need any financial requirements.