It does seem a little strange in that there are heavier pieces of gear to worry about. But why not, back in the day we use to wear our weight belts under our shirts on the flight from TJ to Cabo to avoid paying ridiculous Mexican Airlines baggage fees. We were diving off our own boat and too cheap to buy extra weights. Clearly that was in the days before metal detectors (circa 1978) and it felt unbelievably good to dump that sucker on the seat cushion after lugging it through the airport. I remember being very happy when a shop opened we could rent from.
Which brings up a good point, why not rent the BC in Hawaii?
What ever works,