Asking for a friend
...really, because I'm American. For a citizen of Chile I understand they currently get 90-day visa exempt stamp upon entry (not the 60 days offered to many other nationalities.) Can this be extended for 30 days one or more times at an immigration office in country? This person has entered Thailand one time this year and stayed less than 30 days, and may enter again next month after being out of the country 2-3 weeks.
As they might want to stay here beyond 4 months, they may need to leave Thailand to get a new stamp. If they go to Cambodia, do you expect that will be easy and will they have to stay overnight in Cambodia? Would it be any different if they did a land crossing or if they traveled by airplane?