My experience in the past few years is that the yellow Elite tag works at LAX and TPE, of course by the time Elite pax have gotten through customs, the Premium Laurel pax have left with their luggage already. Elite tagged bags then come out, which we retrieve and depart with before Economy bags arrive. I also recall that crew luggage came out around the same time, maybe just before Elite tagged bags.
Agreed on the 777s, they've been a great addition to BR's fleet.