Just wanted to bump this thread as I am flying on the JL44 on Sunday at 19:20 but wanted to lounge hop in T3. I'm flying in economy with Oneworld Sapphire status.

So the check-in desks will open at 16:20 and no sooner, is that right?

I can fly hand baggage only if necessary as I am only out there for four nights. Is it possible to check in online and proceed through security earlier if HBO, or does my passport need to be checked by a human being? It's a standard UK passport and will travel under the normal visa on arrival arrangements.