What Are the Requirements for a 12 Month Retirement Visa Extension in Thailand?

Interesting visit to Chiang Mai Immigration today to apply for 12 month extension on grounds of being over 50yrs (AKA retirement visa extension) I am Australian, thus could no longer use the stat dec/notarized letter route. I used the 12 month transfer of 65K baht for this year's financial proof. I had a problem with one international transfer (July 2019) being coded as SMT as opposed to FTT and had been warned by my bank and other expats that my visa extension application would be rejected due to this. In addition to a number of expats insisting that I would not be able to get around this without using an agent. I attended immigration a few weeks ago to pick up the list of requirements, the immigration officer at the information desk stressed at the time that I would not get my extension due to not having 12 FTT coded international transfers. I am happy to report a successful extension, with no agent. Bangkok Bank supplied the paperwork to take to Kasikorn Bank, who understood what was needed to verify that my July 2019 transfer did in fact originate in Australia. Today same information desk officer told me that I needed bank statements back to the date I renewed last year. Even through I renewed 32 days earlier than the end of my previous extension. Had I waited this time to renew closer to my retirement extension expiry date, that would mean going by his belief, that I would have had to ask Bangkok Bank for a 13 month statement instead of 12 months. And I certainly hadn't made an International transfer the month before my current extension ie May 2019 until May 2020 commenced. I think he is wrong on this requirement but he insisted that my bank records had to cover 12 months from when I last extended not the 12 month period of my visa validity! And the Immigration Officer who made the final decision re approving my extension added up all my international transfers from the past year over and over again to ensure that the final total exceed 800K which is not part of the requirement either, as I understand it. Fortunately I always transfer a little extra so I fulfilled this surprise criteria. Plus he kept mentioning "pension" which I don't have, but it was also not my understanding that the 65K a month transfered from overseas was required to come from an actual pension. All's well that ends well, I guess, but expect to be thrown a few curve balls depending on the immigration officer's interpretation of the requirements