Kaumalapau likeliest for expansion, that is an underused side, just very dry.
Having actually BEEN to that tiny harbor on the side of sheer cliff, I have to wonder WHERE you would expand it - ever beenin there with a swell running ? Gnarly. When the barge-crews can handle the surge, you KNOW it's bad.
Best bet would be a man-made breakwater/marina on the Maui side. Not likely though.