Best way to populate an ocean with procedurally placed islands?

I am working on a large open world game that consists mainly of open water with scattered hand crafted islands and am wondering what the best way to do that would be.

My initial idea would be to make the islands as their own level, and use them as tiles in world composition. However I can find no documentation as to whether UE4 supports changing the tiles in world composition via code, so I am wondering if that is even possible, or if there is a superior way.

Thanks in advance for any ideas.