that’s Thai bureaucracy for ya. Unless it’s carved in stone not even the people who legislate these things really know. The whole thing is shrouded in contradictories and vagueness.
I’ll add another comment about my experience this year.
I arrived end of January on a TR visa which I extended 60+30. I then went to Vietnam for the weekend then came back on visa exemption which i extended 30+30. After that I did a solo border run which was a terrible and expensive idea. Little did I know the land border I chose was known for militant IO’s. At first they denied me entry grilling me for my visit history in late 2022 early 2023, and said come back tomorrow (for various reasons I could not) so i gave some guy 5000 baht and he talked to someone in the IO office in which I was then granted entry on another exemption which i extended again 30+30.
After that I went back the UK for a little over a month. I then came back with a TR visa, I know I can get 60 days with exemption now but I thought a proper visa would look better.
Anyway going through immigration at bkk the IO said I didn’t need a tr now as it same length as exemption, he then asked where I was going and I said getting another flight to chiang mai, he warned me about flooding and I said I’m aware thank you then stamped me through.
I’d get a DTV but I don’t qualify as I don’t have a spare £10k just sat there lol.