What are the current rules for receiving a visa exemption upon re-entering Thailand after visiting Vietnam?

The user inquired about the duration of stay they would receive upon re-entering Thailand after a trip to Vietnam, having initially entered Thailand without a visa. Comments indicate that while the rules have remained stable since July 2024, there may be scrutiny from immigration officials based on travel patterns suggesting an attempt to frequently reset tourist visa allowances. To smoothly re-enter, it's advised to provide an onward ticket, proof of sufficient funds (20,000 THB), and accommodation bookings.