With a non-O visa/extension the restriction on employment is only within Thailand. Many non-O holders are FIFO workers who are in and out of Thailand on a regular basis. This practice is fine, and the monthly transfers of 65k can be from overseas employment. Although I'm not a FIFO worker, my first three years in Thailand, I was still working in my law firm for six months of the year. I had no pension at that stage, but Bangkok Immigration do not ask to see where the money from overseas comes from. I also moved around Thailand a bit for several years and other immigration offices I used similarly simply accepted the monthly transfers. The only criteria is the money MUST be transferred from overseas