I had family death and flew to Vietnam after entering Thailand for two weeks with DTV. I came back into Thailand without any questions. I then left to another country for businesses a month later. I came back into Thailand without any questions.
I have TagThai. It is horrible. You only can pay for businesses that have Bussiness QRcode. The app is very slow. Additionally you have to use foreign currencies to exchange or top-up the account. Their exchange rate is bad!! Moreta app is the same but at least they give you the current rate. I would go with Moreta. I am waiting to use all my money in the TagThai.