On the limited information so far, If resident and paying tax in a country without a DTR the tax paid in the home country is disregarded. Most countries have a form of tax relief to deal with this - say 3/4 of the overseas tax is an allowable deduction - but this is unlikely to be addressed in Thailand when something as simple as taxing gains and not allowing losses is currently the practice.
So for the foreseeable future I will spend less than 180 days in Thailand and my Partner can stay with me for 180 days in my Country - so not many days for me to spend elsewhere. I get free medical care in my home Country but would have to pay in Thailand. Cannot see another option until legislation is passed. At least my Country does not have a TIEA (exchange of information arrangement) with Thailand.