This is big news if that's the case, although it's not really clear from the PG website. They've definitely changed their policy... "Separated Ticket which was issued by all airlines, can not be checked through" (sic)

But on another page, it then suggests that "for Airlines under agreement with Bangkok Airways. - Passenger must request for through check-in upon check-in at the airport as well as providing detail of the second ticket", and then bags are checked through as normal. And airlines under agreement seems to be most non-*A airlines according to the first page

Does anyone know what's actually going on?!