I opened a tourist Bangkok bank account in Aonang back in December. Only needed a letter of residency which I obtained from Krabi Town immigration office with a payment of gratitude. Document needed a receipt of tm3 from hotel (I got away with a hotel confirmation) & your passport. Only downside is only bank account & atm card provided, no online banking account. However, I can use the account for most transactions as transferring money from my foreign bank account via wise, grab/lazada online purchases,... tip: just need to find the right bank location.