TagThai is a payment app that can scan at 7/11 s etc, just like Thai bank apps. I am pretty sure is owned by the Thai government or at least is recommended by then. I know some tourists use it. You are probably a different type of tourist than the two week, holiday crowd, who I think mostly don't care much about exchange rates but it does save them the 250+ ATM fees, even if the rates are probably bad as you say. As they sY, T.I.T. The government continually says they are aiming at a cash free economy but then try to get every tourist to carry cash.