well, if one meets the visa extension requirements of having the funds on deposit for two months there will be no problem obtaining the letter from the bank. I don’t see a problem if one is complying with Thailand’s immigration requirements.
I’ve come in several times. All I did was show my passport. Each time at BKK.
If you want to feel reassured, just screenshot the area showing the QR code and some of the boxes below showing your name, passport number, etc and keep it in your photos on your phone. You’ll be fine because it’s all in their system and related to your passport number. Cheers!
Ask your rental agent if he has information on what banks in the area require of you to open an account. Usually need a lease and a non immigrant visa. You’ve got the non o do maybe just the lease then. Some banks may require a residence certificate from immigration.