We have been traveling LAX to SIN 2 or 3 times a year on Singapore Airlines since 1999, and this May we made the mistake of sitting in the front of the boarding area because DebF had knee surgery about 3 weeks before the flight and we needed to have early boarding so she would be able to board without problems or getting run over by small women in a hurry to board.
BIG MISTAKE, they nabbed my roll-a-board because it was a tad heavy at about 19 kilos. I unloaded it into my backpack and her 2nd carry on and gave them an empty roll-a-board which they supposedly gate checked 1 hour prior to departure. IT was not on the flight with us to SIN and then on to Bali.
The gate Nazis also hassled 2 elderly women in wheel chairs and took their carry ons away from them at that time. One of them was traveling by herself and she was in tears. There was absolutely no need for her to get hassled.
I watched as the 350 or so passengers got on after we did and there were many with back packs almost as large as my 2 checked bags that had to weigh 25-30 kilos each, some folks had 4 carry ons, many of them larger than the one they made me give up and they had absolutely no problems whatsoever.
This is the first time either of us has been hassled about the number of, or the weight of our carry ons.
We did get my carryon delivered to our hotel in Ubud one day after we arrived in Bali thanks to the lost baggage service in the DPS aiport. It is 1000% better than American Airlines (AA) at finding missing luggage and forwarding it in a timely manner.
IF your luggage goes missing on AA the best thing you can do is search all the luggage areas at all of the AA gates, you will probably find it there, AA will never will.
So to summarize: Stay in the middle or back of the boarding areas for Singapore airlines, don't look at the agents, just be cool and you should be good to go with 2 carryons, possibly 3.