There is no extra stamp from immigration if you leave Thailand within 24 hours of visa expiry. You don't have to go to the overstay desk, and you are just stamped out as usual.
With a tourist visa, you get a 60-day stamp on arrival, which can be extended for 30 days for a payment of 1,900 Baht. You can also extend again for the same payment but you only get 7 days, which can be useful in certain circumstances but is not very cost effective
Tod Daniels That was my experience with non-immigrant visas, but apparently Paul Gibbons is having a different experience with the METV – unless he had triple entry visas and is mixing them with multiple.
Sounds like a mistake, but it could make sense - in other words they would issue only one kind of tourist visa but alter the duration. Maybe they had run out of the SETV stickers.