For all interested, with my on arrival visa about to expire January 1st 2026, I travelled to Laos December 30th, spent 2 nights there as required by Thai immigration and then re entered Thailand on January 1st. I now have a new 60 day on arrival visa stamp in my passport. I am a US passport holder
I did this with proof of accommodations, bank statement, ample baht, and proof of departure in march. Immigration did not ask to see any of these photocopies. I only presented my passport and digital arrival card.
I’m not saying you will have the same experience under similar circumstances but this is the way it went for me through Chiang Khong.
Best of luck to all who love Thailand and wish to extend their stay.
Happy new year, friends