I think that most informed and smart people will stay <180 days just to stay out of the radar in Thailand, who knows what they gonna crack down on next.
April and May were hot like hell's kitchen this year, and even I plan to head somewhere cooler for that 2 months (2nd country).
That leaves 4 months to spend in a 3rd country and not be︀ a tax resident anywhere.
Negatives: if you rent a condo or house, it will have︁ to stay empty for half year.
But there are alternatives like Vietnam, Cambodia and Laos︂ (and Myanmar, if you feel lucky), where the local government is decades behind and leaves︃ you alone.