Nice video. It seems that they could have been introduced by Spanish merchants returning from China on the Pacific trade routes. It could make a useful trade good with the natives with limited military advantage against Europeans compared to trading them gunpowder.
I do agree with your conclusion that construction techniques of the Asiatic bows would probably have been a limiting factor in adoption, making it primarily a prestige item. But that said, I wouldn't discount native craftsmen and their ability. If they really are superior to local bows I'd be surprised if significant Asiatic influence didn't start to show up in local weapons.