All I can say is read my first post, everything is explained there. but I'd like to say it again. without visa. So stamp on arrival, that's not a visa. Dot the permission 180 days maximum of which 90 days in 6 months
But as you certainly know and as it is written down in Thai law, the text regulation of the individual visa takes precedence over the general text regulation. That's why you always enter with a tourist visa or other visa so that you can't reach these 180 days.
According to the latest regulations, anyone who stays in the country for longer than 180 days is considered a permanent resident and is therefore subject to tax. To prevent this from happening, a limit has been set for 180 days without a visa...this is what i heard from the visa agents or my lawyer in Thailand.