Thanks for the replies all. I was indeed already enroute from JKT to SIN by the time you replied.

As it turned out, the SIN to EWR leg was full in Raffles, though if I had read your replies in time, I would have raised the topic while waiting in the Silver lounge at SIN between legs. The econ section was less than half full, so I actually had a nice time of it all by myself in my favorite seat...43k. Nobody for 3 or 4 rows in any direction. But still... at least now I know roughly how to do this in the future. thx!