Can my friend with a work permit return to Thailand immediately after leaving or must he wait until his visa expires?

The user is inquiring about the implications of leaving Thailand with a work permit and a non-B visa. Key points from the discussion indicate that the friend should cancel his work permit before leaving, usually with a termination letter submitted to the labor department. If he leaves before May 20th, his visa will expire upon exit unless he has a re-entry permit. Returning the next day should be possible but may be contingent on visa terms, and a 60-day stamp could be received if eligible for visa exemption upon re-entry.