I almost always use my 88 or 83 Radical Thruster Quad and 4.5-5.0. There are 4.2 days and some lighter days, but Maui is a pretty windy place. As soon as Windguru says 10 knots from the east, you can pretty much guarantee sailing on a 5.0 or 4.7, so it is the perfect place to score a lot of sailing. Ho’okipa is also the windiest part of the island on normal trade wind days. You can sometimes be sailing Ho’okipa on a 5.0 when it’s glassy and calm at Kanaha, just due to the direction of the wind.
I would say that it’s best to use a bigger board than you would think and a smaller sail. I tend to go for more volume there than normal because of the current etc. As soon as you get on the wave, the side-offshore wind and the speed of the waves makes you feel overpowered quickly, so the big board/small sail combo is generally the preferred setup.