Well yes, you can do it, maybe carrying a ticket out of the Thai, and in some neighboring countries you pay an entry. I honestly always go out for maleysia and there are no entry costs. but it is better for you to leave laos or vietanm. but spend on travel etc. if you also like this type of experience is fine. but to make it shorter in immigration would be the best thing, and savings and minimum!
Hello, you can very well take an extension on immigration also on the last day of the 30 days and I think they give another 30 days paying the 1900 baht tax. yes, you can also go out and come back and get the same days by land. But I think it is more feasible to make a normal extension on immigration in the city where you are at the moment.