Can I extend a 30-day visa exempt stamp from a border crossing and re-enter Thailand for another 30 days?

Yes, a 30-day visa exempt stamp obtained from a border crossing can be extended for an additional 30 days at any local Immigration Office. After extending, travelers can re-enter Thailand from a neighboring country like Malaysia. However, travelers should be cautious as there are restrictions on the number of times one can use land borders for visa exemptions within a calendar year, which is typically limited to two entries for certain passport holders.