My HKG - SYD last week had the J line marked OWE/DM, there was then a OWS/GO line behind this roped off to hold back the 'inferior' elites. I hadn't seen this before but it makes sense.

Either way if you are at the gate prior to boarding then you can pretty much guarantee boarding before anyone in Y as they clear these lines first before general boarding which is nice.

Have never seen anyone so brazenly try to cut the line based on status but have certainly stopped others from cutting in front, people will try anything on and it's always nice to see CX rules firmly applied to cut these fools down to size.