So I just stumbled across a Skype username to contact Royal Jordanian, which is apparently a 24-hour service (very impressed!). The lady informed me that One World benefits would not include the extra baggage, but to be honest since I'm only going to be charged ~300 THB/kg, it won't matter if we're a few kg over. Will probably call again later to check what benefits I would get (particularly in light of jahason's lack of Crown Class check in with OW Emerald).