Apologies if this has already been discussed.
IIUC, the "normal" method for land ownership is to hold it in name of Thai spouse, with the foreigner "enjoying" tenancy at-will.
What is the disposition of the land when the Thai spouse dies? Especially if there are no children of record, and no will/testament?
Will the surviving (foreign) spouse inherit the property? Will it go to the nearest Thai relative? Will it escheat to the government?
[No, I am not planning some villainous end-run around the law]