Please clarify a 30 day extension to a 60 day visa exempt visit to Thailand scenario . If I arrive at BKK on October 1 I will be stamped for 60 days until November 29. If I go to Vietnam during this time, and come bacK to BKK and get a 30 day extension until December 29 , can I simply change flights and depart Thailand and go back to America on December 29 with no issues ? Thanks in advance for your advice..k