Ok I can only speak for Bangkok. If you have a minimum of 12 months of unbroken monthly transfers from overseas of minimum 65k this can be used in lieu of the 800k lump sum. It effectively replaces the embassy affidavit method for those countries whose embassies will no longer provide the certification. That's Bangkok. Since I've done the conversion a couple of years ago, I know two other people personally who have also obtained the non-O without the lump sum.
Ok. Turn to petty insults. Sticking to facts, a person can be a dual tax resident. That's a fact. In this case there is a tie-break process to determine actual tax residency. That's a fact. If the tie-break process determines the person is a tax resident of another country, there is no requirement to file a tax return in Thailand, as the other country has sole taxation rights. That's a fact. This does not apply to everyone as each individual has different circumstances. That's a fact.
I actually switched from a visa-exempt entry. It's not possible to go directly from OA to O. It was accepted because I had sufficient monthly transfers to meet the criteria.
It depends on your tax residency, source of income, tax already paid. All three of those can mean you pay zero tax in Thailand, or conversely they mean you do pay tax. Every individual is different. There is no generic formula. Unfortunately many people have been duped by unscrupulous tax agents into believing that anyone in the country for 180 days or more must pay tax, which is totally incorrect
I switched from OA to O via a visa exempt in Bangkok, and used the 65k transfer method. I never once had the 800k lump sum. I guess some immigration offices use their own set of rules
If you're into financial planning, you should be aware that you don't pay tax twice. I've lived in Thailand for over 15 years and never had to pay income tax here. I do pay substantial tax in my home country as I have dual tax residency, hence I am not required to pay tax in Thailand. It's not a case of "winging it", it's a case a solid financial planning