My next trip - HBA-MEL-SYD-NRT-LAX-SYD premium redemption extravaganza

[AV8]

Can confirm that Qantas serve a light supper in J on the Sydney-Tokyo run, not a dinner service.
Q Eat includes an exclusive online option, which is cheese and crackers. The other options are actual proper light meals.
I would have expected a bit more than that in J - usually got a full dinner even with midnight departures in Economy with EY, Emirates and SQ.

When I did this leg in July there was a Chicken Schnitzel sandwich (amongst other selections) available which could be pre ordered on line about 7 days before departure - full dinner service was not offered.