I've grown them in south and central Florida for the last 35 years, sometimes shaded, often in full sun. They really don't care. But I think the Brazilians are correct that you get more fruit on a full-sun tree. True, the upper leaf canopy always looks a bit burned. But they grow and produce heavily anyway.
Kona coffee -- I don't know if it's just one cultivar, but it is C. arabica, and it is propagated from plageotropic (great dinner party word, that -- means taken from the horizontal-growing branches) cuttings, so the trees are lower and bushier than seedling coffee.