I have done both routes. I don't think "resupply concerns" comes into the equation.On leaving Panama
City you know that the next supermarket is in Papeete, and that you are not going to see descent prices for provisioning
until NZ/OZ.So just fill your yacht with food
I did the Mangareva route in 82, an saw 2-3 other yachts. At that time there was restrictions in force due to the closeness of Mururoa, and some dumping of waste in the lagoon
, that maybe kept cruisers away. I never heard anything of it, and did not know about the restrictions in the first place.
By the way, the fascinating history
of the Polynesian settlement in this part of Oceania is well worth looking into. There was an established trading route between Mangareva and Easter Island, that in the end collapsed due to a man made environmental disaster on Easter Island. Start with searching Wikipedia for Easter Island.
I wished I knew the history
when I passed through. Jared Diamonds book "Collapse" has a fascinating chapter about this area that covers all these Islands.