correct, I'm doing exactly the same. Additional benefit that if you stop working or change job, no need to apply for visa again. Plus, the process of work permit much faster if it's not linked to non-b visa.
So visa run is the only option with this visa? Last time i left the country, i accidentally overstayed and had to pay a penalty. Then the immigration officer told me, that if i don't want to travel, i have to report at Chaengwattana.