I did this a few years ago
IKK'ed YYZ-LAX for the morning flight
We spent the day in LAX
then, using my Amex points via Delta I was able to grab 2 J rewards on Air Tahiti Nui.
It cost me probably about $800 in YQ on the DL ticket.
11/10 would do it again. Although, I would say skip Bora Bora as there are better places down there to go to