he could do that but he'd get a 30 day under consideration stamp cancelling the employment extension and applying for a marriage extension and then need a re-entry permit to keep that 30 day stamp alive so he could come back as well has having to coordinate a home visit (if they did one) while he's traveling out and back.
Good suggestion though
@John *********
(y) , and I'd say
@James *********
should think about coming in visa exempt and applying for the married to a thai Non-O then the year extension (if they meet the requirements) as then no matter if he worked or not the extension wouldn't change between jobs because it'd be issued based on marriage