Hawaiian Islands have 75 degrees average temperature year round, various amounts of rainfall depending on where you are on the islands, and about a 15 mph breeze off the Pacific virtually every day. Factor in the volcanic loam and I am not sure that you could ever get a tree to thrive anywhere else... perhaps Tahiti.
O.K, here's a long lecture on tropical forestry.
Actually there are a lot of similar regions throughout the tropics. In Central America, probably half the western coast has those conditions. Species movement around the tropical world has been going on for centuries. The Monkeypod in Hawaii, for example, is a Central American native we call
Cenizaro. We also have wide plantings of Tamarind (
Tamarindo) which is an Asian native.
Usually there are specific reasons for this happening. In the case of Cenizaro, it was taken to Hawaii because it is such a beautiful ornamental. We brought in Tamarind because of it's delicious fruit.
No one that I know of has brought Koa to our region - then again, we already have more beautiful tropical hardwoods than probably any place on earth. There have been, however, two notable movements of trees for the purpose of timber.
Teak has recently come to Central America - it is a dense wood with a much faster growth rate than our natives, and has been widely planted on plantations. It is such a recent development (1980s) that there are still no fully mature trees, but evidence so far is that the quality is equal to Asian growth.
The other planting was much earlier. Santo Domingo Mahogany (Swietenia Mahogoni) is that beautiful dense mahogany - characteristics are almost between a Mahogany and a Rosewood. It was the first mahogany exported from the new world. It has been thought by many to be almost extinct. The last big native stands were cut by the Cubans and sent to the Soviet Union in the 1960s.
What most don't realize is that there is still a lot of it around. The Dutch, in their colonial days transported it from their Caribbean colonies to Indonsesia. There are huge stands of it there, where the government prohibits it's export in anything but finished goods.
I have seen the Caribbean material in antique furniture and a few old boards, and the Indonesian wood in newly built furniture exports. While those surviving antiques had better selected boards than a lot of what comes out of Indonesia now, to me, it appears that the overall quality of the Asian wood is just as good as the Caribbean.
To sum up, Koa could be grown in a lot of places in the tropics. Quality would likely vary as it would in Hawaii, with some sites being more favorable than others.
The End