This is my exact thought as well as the multiple flights entering and exiting Thailand. I can understand one entering and exiting. But if you exit via land as well you'll have no proof
So just get my new passport. And bring them both back to thailand. Show the visa in my old book and get the stamp in my new book. And do this until my visa expires basically? Thank you for the help and if I seem repedative. I'm just paranoid I'll waste a 200 dollar visa by screwing this up
Do I still need the letter from a US consulate if I am currently in the US? I would receive my new passport before entering thailand again as well as continue to have my old passport.