Yes the Thai tax year follows the calendar year so as long as you don’t spend 180 days in a calendar year within Thailand you will not become tax resident.
that’s exactly how it previously worked for many years. Now the same process produces a different result which is what everyone is complaining about. Now it doesn’t code as an international transfer in the receiving Thai bank.
All can be done relatively easily without help but if you are determined to use an agent then go see Maneerat on Soi Post Office in Pattaya. Highly recommended.