@Raphie ***
DO NOT FLY INTO THAILAND when you Bounce out to Vietnam. RETHINK your plan...Use ONLY LAND BORDER ENTRIES... AVOID POIPET BORDER CROSSING.
Read this recent reply...
"Just an aside, IF you do have an extensive entry/stay history to thailand, about all you can do is have the 3 proofz
proof of 20K baht or the equivalent in CASH
proof of onward travel in the number of days you'll get stamped in for
proof of lodging (at least for a week)
IF they're going to pull you aside, question you about your entry history and possibly deny you entry, they'll ask for onward travel FIRST and showing them that you're flying out in 30 days (the number of days you get on a visa exempt entry) is about the only thing that might sway them from shipping you back out on your dime π /
Sincerely good luck with it, safe travels"