I have income but my country. I get my salary every month there. But I pay my expenses in Thailand with the Thai QR linked to my home country bank account, so the money goes straight from my home country bank account to the Thai vendor. I haven't done any remittance, and only withdrew cash from the ATM once, to try if it worked.
If you want to do not include something, ask the bank, don't change it or mark it yourself. In my case, for instance, I asked the bank to issue it only showing only the deposits of ㅇㅇㅇ (the company I work for) from xx month to xx month.
In my case, my non Korean passport was issued in Korea. On Place of issue I wrote Seoul, and my DTV was approved. I got it trhu the Thai Embassy in Korea.
As this is a DTV group, I'm assuming you have a DTV, hence you're banned to make income from within Thailand. If you remit money, then you might end up paying tax but only for the remitted amount.
It's not based only on where you live, but also on whether you remit money here. There are some legal requirements you must meet to pay taxes here. If you fulfill them, then yes, you must pay taxes. But it's not something you can choose only because the rate is lower than in your country. If your salary is not from here and you don't remit money here, you can't pay, even if you wanted to.
I have no income from Thailand and I remit no money, so I don't have to pay taxes here. Period. I do pay a lot of taxes in my home country, even if I don't physically live there, as my salary is from there.