Juul Labs Inc., maker of the controversial and top-selling Juul electronic cigarette, is attempting to use Bluetooth technology as a way to limit youth usage of its products. However, the strategy is unlikely to be rolled out domestically for years since it would require Juul Labs to successfully complete a daunting Food and Drug Administration regulatory gauntlet. Juul continues to expand its market share gap with R.J. Reynolds Vapor Co.’s Vuse at 70.5 percent to 10.8 percent, respectively.