My understanding is that you need the Medical Insurance for your initial Long Stay OA visa and also for future 12 month extensions. If you google Long Stay Visa Medical Insurance Thailand you should find the relevant info. For example
is full of shit. I've lived in Papaya, Korat and Ko Samui and I've reported on the Monday because Immigration was closed when I've returned either late on a Friday nite or on a Saturday. Never had a problem, and if there ever had been, I'd have immediately asked to speak to the boss.
Guarantee you that more Indians per head of capita are kicked out of Thailand than Aussies or Kiwis combined. I’ve been approached many times in Bangers by your dodgy mates on the street trying to flog fake watches. Work permits........don’t think so. So pull ya head in mate.
you can ask for a stamp. Gov employees often need details of travel for security clearances and the easiest way is to just look at the departure and entry stamps in a passport.